Document Outline

Features
Options
Ball Assignment (Top View)
Key Timing Parameters
Pin Assignment (Top View)
256Mb SDRAM Part Numbers
General Description
Table of Contents
Functional Block Diagram
Ball Descriptions
Pin Descriptions
Functional Description
Initialization
Register Definition
- Mode Register
- Burst Length
- Burst Type
- CAS Latency
- Operating Mode
- Extended Mode Register
- Temperature Compensated Self Refresh
- Partial Array Self Refresh
- Deep Power Down
- Driver Strength
Figure 1 Mode Register Definition
Table 1 Burst Definition
Figure 2 CAS Latency
Table 2 CAS Latency
Commands
- Command Inhibit
- No Operation (NOP)
- Load Mode Register
- Active
- Read
- Write
- Precharge
- Auto Precharge
- Auto Refresh
- Self Refresh
Truth Table 1 - Commands and DQM Operation
Operation
- Bank/Row Activation
- READs
- WRITEs
- PRECHARGE
- Power-Down
- Deep Power-Down
- Clock Suspend
- Burst READ/Single WRITE
- Concurrent Auto Precharge
Figure 3 Activating a Specific Rown in a Specific Bank
Figure 4 Example
Figure 5 Read Command
Figure 6 CAS Latency
Figure 7 Consecutive READ Bursts
Figure 8 Random READ Access
Figure 9 READ to WRITE
Figure 10 READ to WRITE with Extra Clock Cycle
Figure 11 READ to PRECHARGE
Figure 12 Terminating a READ Burst
Figure 13 WRITE Command
Figure 14 WRITE Burst
Figure 15 WRITE to WRITE
Figure 16 Random WRITE Cycles
Figure 17 WRITE to READ
Figure 18 WRITE to PRECHARGE
Figure 19 Terminating a WRITE Burst
Figure 20 PRECHARGE Command
Figure 21 Power-Down
Figure 21a Deep Power-Down
Figure 22 Clock Suspend During WRITE Burst
Figure 23 Clock Suspend During READ Burst
Figure 24 READ with Auto Precharge Interrupted by a READ
Figure 25 READ with Auto Precharge Interrupted by a WRITE
Figure 26 WRITE with Auto Precharge Interrupted by a READ
Figure 27 WRITE with Auto Precharge Interrupted by a WRITE
Truth Table 2 - CKE
Truth Table 3 - Current State Bank n, Command to Bank n
Truth Table 4 - Current State Bank n, Command to Bank m
Absolute Maximum Ratings
DC Electrical Characteristics and Operating Conditions - LC Version
DC Electrical Characteristics and Operating Conditions - V Version
DC Electrical Characteristics and Operating Conditions - H Version
Capacitance - FBGA
Capacitance - TSOP
Electrical Characteristics and Recommended AC Operating Conditions
AC Functional Characteristics
IDD Specifications and Conditions
IDD7 - Self Refresh Current Options (Temperature Compensated Self Refresh)
Notes
Initialize and Load Mode Register
Power-Down Mode
Clock Suspend Mode
Auto Refresh Mode
Self Refresh Mode
Read - Without Auto Precharge
Read - With Auto Precharge
Single Read - Without Auto Precharge
Single Read - With Auto Precharge
Alternating Bank Read Accesses
Read - Full-Page Burst
Read - DQM Operation
Write - Without Auto Precharge
Write - With Auto Precharge
Single Write - Without Auto Precharge
Single Write - With Auto Precharge
Alternating Bank Read Accesses
Write - Full-Page Burst
Write - DQM Operation
54-Pin Plastic TSOP (400 mil)
VFBGA "FG" Package 54-Pin, 8mm x 14mm

256Mb: x16 Mobile SDRAM
MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

PRODUCTS AND SPECIFICATIONS DISCUSSED HEREIN ARE FOR EVALUATION AND REFERENCE PUROPOSES ONLY AND ARE SUBJECT TO CHANGE BY

MICRON WITHOUT NOTICE. PRODUCTS ARE ONLY WARRANTED BY MICRON TO MEET MICRON'S PRODUCTION DATA SHEET SPECIFICATIONS.

16 Meg x 16

Configuration

4 Meg x 16 x 4 banks

Refresh Count

Row Addressing

8K (A0A12)

Bank Addressing

4 (BA0, BA1)

Column Addressing

512 (A0A8)

MOBILE SDRAM

BALL ASSIGNMENT (Top View)

54-Ball VFBGA

FEATURES

· Temperature Compensated Self Refresh (TCSR)
· Fully synchronous; all signals registered on

positive edge of system clock

· Internal pipelined operation; column address can

be changed every clock cycle

· Internal banks for hiding row access/precharge
· Programmable burst lengths: 1, 2, 4, 8, or full page
· Auto Precharge, includes CONCURRENT AUTO

PRECHARGE and Auto Refresh Modes

· Self Refresh Mode
· 64ms, 8,192-cycle refresh
· LVTTL-compatible inputs and outputs
· Low voltage power supply
· Deep Power Down
· Partial Array Self Refresh power-saving mode

OPTIONS

MARKING

· V

3.3V/3.3V

2.5V/2.5V1.8V

1.8V/1.8V

· Configurations

16 Meg x 16 (4 Meg x 16 x 4 banks)

16M16

· Plastic Packages OCPL

54-pinTSOP (400 mil)

54-pinTSOP (400 mil) Lead-Free

54-ball VFBGA (8mm x 14mm)

54-ball VFBGA (8mm x 14mm) Lead-Free

· Timing (Cycle Time)

8.0ns @ CL = 3 (125 MHz)

-8

10ns @ CL = 3 (100 MHz)

-10

· Operating Temperature

Commercial (0

C to + 70

None

Industrial (-40

C to + 85

NOTE: 1. Contact Factory for availability.

2. Due to space limitations, FBGA-packaged compo-

nents have an abbreviated part mark that is different
from the part number. See our Web site for more
information on abbreviated component marks.

KEY TIMING PARAMETERS

SPEED

CLOCK

ACCESS TIME

SETUP HOLD

GRADE

FREQUENCY

CL=1* CL=2* CL=3*

TIME

-8

125 MHz

7ns

2.5ns

1.0ns

-10

100 MHz

7ns

2.5ns

1.0ns

-8

100 MHz

8ns

2.5ns

1.0ns

-10

83 MHz

8ns

2.5ns

1.0ns

-8

50 MHz

19ns

2.5ns

1.0ns

-10

40 MHz

22ns

2.5ns

1.0ns

*CL = CAS (READ) latency

MT48LC16LFFG, MT48LC16M16LFBG,
MT48V16MLFFG, MT48V16M16LFBG,
MT48H16M16LFFG, MT48H16M16LFBG
4 Meg x 16 x 4 banks

For the latest data sheet revisions, please refer to the Micron
Web site:

www.micron.com/dramds

1 2 3 4 5 6 7 8

DQ14

DQ12

DQ10

DQ8

UDQM

A12

DQ15

DQ13

DQ11

DQ9

A11

CKE

CAS\

BA0

DQ0

DQ2

DQ4

DQ6

LDQM

RAS\

BA1

DQ1

DQ3

DQ5

DQ7

WE\

CS\

A10

VDD

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

PART NUMBER

ARCHITECTURE

PACKAGE

MT48LC16M16LFFG-10

3.3V / 3.3V

16 Meg x 16

54-BALL VFBGA

MT48LC16M16LFFG-8

3.3V / 3.3V

16 Meg x 16

54-BALL VFBGA

MT48V16M16LFFG-10

2.5V / 1.8V

16 Meg x 16

54-BALL VFBGA

MT48V16M16LFFG-8

2.5V / 1.8V

16 Meg x 16

54-BALL VFBGA

MT48H16M16LFFG-10

1.8V / 1.8V

16 Meg x 16

54-BALL VFBGA

MT48H16M16LFFG-8

1.8V / 1.8V

16 Meg x 16

54-BALL VFBGA

The 256Mb SDRAM uses an internal pipelined ar-

chitecture to achieve high-speed operation. This ar-
chitecture is compatible with the 2n rule of prefetch
architectures, but it also allows the column address to
be changed on every clock cycle to achieve a high-
speed, fully random access. Precharging one bank
while accessing one of the other three banks will hide
the precharge cycles and provide seamless, high-
speed, random-access operation.

The 256Mb SDRAM is designed to operate in 3.3V

or 2.5V or 1.8V memory systems. An auto refresh mode
is provided, along with a power-saving, power-down
mode. All inputs and outputs are LVTTL-compatible.

SDRAMs offer substantial advances in DRAM oper-

ating performance, including the ability to synchro-
nously burst data at a high data rate with automatic
column-address generation, the ability to interleave
between internal banks to hide precharge time and
the capability to randomly change column addresses
on each clock cycle during a burst access.

GENERAL DESCRIPTION

The 256Mb SDRAM is a high-speed CMOS,

dynamic random-access memory containing
268,435,456 bits. It is internally configured as a quad-
bank DRAM with a synchronous interface (all signals
are registered on the positive edge of the clock signal,
CLK). Each of the x16's 67,108,864-bit banks is orga-
nized as 8,192 rows by 512 columns by 16 bits.

Read and write accesses to the SDRAM are burst

oriented; accesses start at a selected location and con-
tinue for a programmed number of locations in a pro-
grammed sequence. Accesses begin with the registra-
tion of an ACTIVE command, which is then followed by
a READ or WRITE command. The address bits regis-
tered coincident with the ACTIVE command are used
to select the bank and row to be accessed (BA0, BA1
select the bank; A0A12 select the row). The address
bits registered coincident with the READ or WRITE com-
mand are used to select the starting column location
for the burst access.

The SDRAM provides for programmable READ or

WRITE burst lengths of 1, 2, 4, or 8 locations, or the full
page, with a burst terminate option. An auto precharge
function may be enabled to provide a self-timed row
precharge that is initiated at the end of the burst se-
quence.

256Mb SDRAM PART NUMBERS

MT48LC16M16LFTG-10

3.3V / 3.3V

16 Meg x 16

54-PIN TSOP

MT48LC16M16LFTG-8

3.3V / 3.3V

16 Meg x 16

54-PIN TSOP

MT48V16M16LFTG-10

2.5V / 1.8V

16 Meg x 16

54-PIN TSOP

MT48V16M16LFTG-8

2.5V / 1.8V

16 Meg x 16

54-PIN TSOP

MT48H16M16LFTG-10

1.8V / 1.8V

16 Meg x 16

54-PIN TSOP

MT48H16M16LFTG-8

1.8V / 1.8V

16 Meg x 16

54-PIN TSOP

Note: 1. Lead-Free packaging partnumbers: Replace the FG with BG for VFBGA and replace the TG code with P for TSOP.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

TABLE OF CONTENTS

Functional Block Diagram 16 Meg x 16 ..............

54-Ball FBGA Pin Description ...................................

54-Pin TSOP Pin Description .....................................

Functional Description ..........................................

Initialization ...........................................................

Mode Register ...................................................

Burst Length ................................................

Burst Type ....................................................

CAS Latency ................................................ 10
Operating Mode ......................................... 10
Write Burst Mode ....................................... 10
Extended Mode Register ............................ 11
Temperature Compensated Self Refresh . 11
Partial Array Self Refresh ........................... 12
Deep Power Down ..................................... 12
Driver Strength ........................................... 12

Commands .................................................................. 13

Truth Table 1 (Commands and DQM Operation)

.............. 13

Command Inhibit ................................................. 14
No Operation (NOP) ............................................ 14
Load mode register ................................................ 14
Active ....................................................................... 14
Read ....................................................................... 14
Write ....................................................................... 14
Precharge ................................................................. 14
Auto Precharge ....................................................... 14
Auto Refresh ........................................................... 14
Self Refresh .............................................................. 15

Operation .................................................................... 16

Bank/Row Activation ........................................... 16
Reads ....................................................................... 17
Writes ....................................................................... 23
Precharge ................................................................. 25
Power-Down .......................................................... 25
Deep Power-Down ................................................ 26
Clock Suspend ........................................................ 26
Burst Read/Single Write ........................................ 27

Concurrent Auto Precharge ................................. 28

Truth Table 2 (CKE)

..................................................... 30

Truth Table 3 (Current State, Same Bank)

...................... 31

Truth Table 4 (Current State, Different Bank)

................. 32

Absolute Maximum Ratings ...................................... 35
DC Electrical Characteristics

and Operating Conditions ................................. 35

Capacitance .................................................................. 36

AC Electrical Characteristics (Timing Table) ..... 37
I

Specifications and Conditions ........................... 39

Timing Waveforms

Initialize and Load mode register ....................... 41
Power-Down Mode ............................................... 42
Clock Suspend Mode ............................................ 43
Auto Refresh Mode ............................................... 44
Self Refresh Mode .................................................. 45
Reads

Read Without Auto Precharge ................... 46
Read With Auto Precharge .......................... 47
Single Read Without Auto Precharge ....... 48
Single Read With Auto Precharge .............. 49
Alternating Bank Read Accesses ..................... 50
Read Full-Page Burst ..................................... 51
Read DQM Operation ................................. 52

Writes

Write Without Auto Precharge .................. 53
Write With Auto Precharge ........................ 54
Single Write - Without Auto Precharge ....... 55
Single Write - Without Auto Precharge ....... 56
Alternating Bank Write Accesses ................... 57
Write Full-Page Burst .................................... 58
Write DQM Operation ................................ 59

Package Dimensions

54-pin TSOP ........................................................... 60
54-pin FBGA ........................................................... 61

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

BALL DESCRIPTIONS

54-BALL FBGA

SYMBOL

TYPE

DESCRIPTION

CLK

Input

Clock: CLK is driven by the system clock. All SDRAM input signals are sampled
on the positive edge of CLK. CLK also increments the internal burst counter
and controls the output registers.

CKE

Input

Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK signal.
Deactivating the clock provides PRECHARGE POWER-DOWN and SELF REFRESH
operation (all banks idle), ACTIVE POWER-DOWN (row active in any bank) or
CLOCK SUSPEND operation (burst/access in progress). CKE is synchronous except
after the device enters power-down and self refresh modes, where CKE
becomes asynchronous until after exiting the same mode. The input buffers,
including CLK, are disabled during power-down and self refresh modes,
providing low standby power. CKE may be tied HIGH.

CS#

Input

Chip Select: CS# enables (registered LOW) and disables (registered HIGH) the
command decoder. All commands are masked when CS# is registered HIGH. CS#
provides for external bank selection on systems with multiple banks. CS# is
considered part of the command code.

F7, F8, F9

CAS#, RAS#,

Input

Command Inputs: CAS#, RAS#, and WE# (along with CS#) define the

WE#

command being entered.

E8, F1

LDQM,

Input

Input/Output Mask: DQM is sampled HIGH and is an input mask signal for

UDQM

write accesses and an output enable signal for read accesses. Input data is
masked during a WRITE cycle. The output buffers are placed in a High-Z state
(two-clock latency) when during a READ cycle. LDQM corresponds to DQ0DQ7,
UDQM corresponds to DQ8DQ15. LDQM and UDQM are considered same
state when referenced as DQM.

G7, G8

BA0, BA1

Input

Bank Address Input(s): BA0 and BA1 define to which bank the ACTIVE, READ,
WRITE or PRECHARGE command is being applied. These pins also provide the
op-code during a LOAD MODE REGISTER command

H7, H8, J8, J7, J3, J2,

A0A12

Input

Address Inputs: A0A12 are sampled during the ACTIVE command (row-

H3, H2, H1, G3, H9, G2,G1

address A0A12) and READ/WRITE command (column-address A0A8; with A10
defining auto precharge) to select one location out of the memory array in the
respective bank. A10 is sampled during a PRECHARGE command to determine if
all banks are to be precharged (A10 HIGH) or bank selected by BA0, BA1 (LOW).
The address inputs also provide the op-code during a LOAD MODE REGISTER
command.

A8, B9, B8, C9, C8, D9,

DQ0DQ15

I/O

Data Input/Output: Data bus

D8, E9, E1, D2, D1, C2,

C1, B2, B1, A2

E2,

No Connect: This pin should be left unconnected.

A7, B3, C7, D3

Supply

DQ Power: Provide isolated power to DQs for improved noise immunity.

A3, B7, C3, D7,

Supply

DQ Ground: Provide isolated ground to DQs for improved noise immunity.

A9, E7, J9

Supply

Power Supply: Voltage dependant on option.

A1, E3, J1

S S

Supply

Ground.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

PIN DESCRIPTIONS

54-PIN TSOP

SYMBOL

TYPE

DESCRIPTION

CLK

Input

Clock: CLK is driven by the system clock. All SDRAM input signals are
sampled on the positive edge of CLK. CLK also increments the internal
burst counter and controls the output registers.

CKE

Input

Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK
signal. Deactivating the clock provides PRECHARGE POWER-DOWN
and SELF REFRESH operation (all banks idle), ACTIVE POWER-DOWN
(row active in any bank) or CLOCK SUSPEND operation (burst/access in
progress). CKE is synchronous except after the device enters power-
down and self refresh modes, where CKE becomes asynchronous until
after exiting the same mode. The input buffers, including CLK, are
disabled during power-down and self refresh modes, providing low
standby power. CKE may be tied HIGH.

CS#

Input

Chip Select: CS# enables (registered LOW) and disables (registered
HIGH) the command decoder. All commands are masked when CS# is
registered HIGH. CS# provides for external bank selection on systems
with multiple banks. CS# is considered part of the command code.

16, 17, 18

WE#, CAS#,

Input

Command Inputs: WE#, CAS#, and RAS# (along with CS#) define the

RAS#

command being entered.

15, 39

x16: DQML,

Input

Input/Output Mask: DQM is an input mask signal for write accesses and

DQMU

an output enable signal for read accesses. Input data is masked when
DQM is sampled HIGH during a WRITE cycle. The output buffers are
placed in a High-Z state (two-clock latency) when DQM is sampled
HIGH during a READ cycle. On the x16, DQML corresponds to DQ0-
DQ7 and DQMH corresponds to DQ8-DQ15. DQML and DQMH are
considered same state when referenced as DQM.

20, 21

BA0, BA1

Input

Bank Address Inputs: BA0 and BA1 define to which bank the ACTIVE,
READ, WRITE or PRECHARGE command is being applied.

23-26, 29-34, 22, 35, 36

A0-A12

Input

Address Inputs: A0-A12 are sampled during the ACTIVE command
(row-address A0-A12) and READ/WRITE command (column-address
A0-A8 [x16]; with A10 defining auto precharge) to select one location
out of the memory array in the respective bank. A10 is sampled during
a PRECHARGE command to determine if all banks are to be precharged
(A10 [HIGH]) or bank selected by (A10 [LOW]). The address inputs also
provide the op-code during a LOAD MODE REGISTER command.

2, 4, 5, 7, 8, 10, 11, 13, 42, DQ0-DQ15

x16: I/O Data Input/Output: Data bus for x16

44, 45, 47, 48, 50, 51, 53

No Connect: This pin should be left unconnected.

3, 9, 43, 49

Supply DQ Power: Isolated DQ power to the die for improved noise immunity.

6, 12, 46, 52

Supply DQ Ground: Isolated DQ ground to the die for improved noise

immunity.

1, 14, 27

Supply Power Supply: Voltage dependant on option.

28, 41, 54

Supply Ground.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

FUNCTIONAL DESCRIPTION

In general, the 256Mb SDRAMs (4 Meg x 16 x 4 banks)

are quad-bank DRAMs that operate at 3.3V or 2.5V or
1.8V and include a synchronous interface (all signals are
registered on the positive edge of the clock signal, CLK).
Each of the x16's 67,108,864-bit banks is organized as
8,192 rows by 512 columns by 16 bits.

Read and write accesses to the SDRAM are burst

oriented; accesses start at a selected location and con-
tinue for a programmed number of locations in a pro-
grammed sequence. Accesses begin with the registra-
tion of an ACTIVE command, which is then followed by
a READ or WRITE command. The address bits regis-
tered coincident with the ACTIVE command are used
to select the bank and row to be accessed (BA0 and BA1
select the bank, A0A12 select the row). The address
bits ( x16: A0A8) registered coincident with the READ
or WRITE command are used to select the starting col-
umn location for the burst access.

Prior to normal operation, the SDRAM must be ini-

tialized. The following sections provide detailed infor-
mation covering device initialization, register defini-
tion, command descriptions and device operation.

Initialization

SDRAMs must be powered up and initialized in a

predefined manner. Operational procedures other
than those specified may result in undefined opera-
tion. Once power is applied to V

and V

Q (simulta-

neously) and the clock is stable (stable clock is defined
as a signal cycling within timing constraints specified
for the clock pin), the SDRAM requires a 100µs delay
prior to issuing any command other than a
COMMAND INHIBIT or NOP. CKE must be held high
during the entire initialization period until the
PRECHARGE command has been issued. Starting at
some point during this 100µs period and continuing at
least through the end of this period, COMMAND IN-
HIBIT or NOP commands should be applied.

Once the 100µs delay has been satisfied with at

least one COMMAND INHIBIT or NOP command hav-
ing been applied, a PRECHARGE command should be
applied. All banks must then be precharged, thereby
placing the device in the all banks idle state.

Once in the idle state, two AUTO REFRESH cycles

must be performed. After the AUTO REFRESH cycles
are complete, the SDRAM is ready for mode register
programming. Because the mode register will power
up in an unknown state, it should be loaded prior to
applying any operational command.

Mode Register

The mode register is used to define the specific mode

of operation of the SDRAM. This definition includes
the selection of a burst length, a burst type, a CAS
latency, an operating mode and a write burst mode, as
shown in Figure 1. The mode register is programmed
via the LOAD MODE REGISTER command and will re-
tain the stored information until it is programmed again
or the device loses power.

Mode register bits M0M2 specify the burst length,

M3 specifies the type of burst (sequential or inter-
leaved), M4M6 specify the CAS latency, M7 and M8
specify the operating mode, M9 specifies the write burst
mode, and M10, M11, and M12 should be set to zero.
M13and M14 should be set to zero to prevent extended
mode register.

The mode register must be loaded when all banks

are idle, and the controller must wait the specified time
before initiating the subsequent operation. Violating
either of these requirements will result in unspecified
operation.

Burst Length

Read and write accesses to the SDRAM are burst

oriented, with the burst length being programmable,
as shown in Figure 1. The burst length determines the
maximum number of column locations that can be ac-
cessed for a given READ or WRITE command. Burst
lengths of 1, 2, 4 or 8 locations are available for both the
sequential and the interleaved burst types, and a full-
page burst is available for the sequential type. The
full-page burst is used in conjunction with the BURST
TERMINATE command to generate arbitrary burst
lengths.

Reserved states should not be used, as unknown

operation or incompatibility with future versions may
result.

When a READ or WRITE command is issued, a block

of columns equal to the burst length is effectively se-
lected. All accesses for that burst take place within this
block, meaning that the burst will wrap within the block
if a boundary is reached. The block is uniquely se-
lected by A1A8 (x16) when the burst length is set to
two; by A2A8 (x16) when the burst length is set to four;
and by A3A8 (x16) when the burst length is set to
eight. The remaining (least significant) address bit(s)
is (are) used to select the starting location within the
block. Full-page bursts wrap within the page if the
boundary is reached.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

M3 = 0

Reserved

Full Page

M3 = 1

Reserved

Operating Mode

Standard Operation

All other states reserved

Defined

Burst Type

Sequential

Interleaved

CAS Latency

Reserved

Burst Length

CAS Latency

A7 A6

Mode Register (Mx)

Address Bus

M6-M0

Op Mode

A10

A11

Reserved*

Write Burst Mode

Programmed Burst Length

Single Location Access

*Should program

M12, M11, M10 = "0, 0, 0"

to ensure compatibility

with future devices.

A12

BA0

BA1

0 0

NOTE: 1. For full-page accesses: y = 512 (x16)

2. For a burst length of two, A1-A8 (x16) select the

block-of-two burst; A0 selects the starting column
within the block.

3. For a burst length of four, A2-A8 (x16) select the

block-of-four burst; A0-A1 select the starting
column within the block.

4. For a burst length of eight, A3-A8 (x16) select the

block-of-eight burst; A0-A2 select the starting
column within the block.

5. For a full-page burst, the full row is selected and

A0-A8 (x16) select the starting column.

6. Whenever a boundary of the block is reached

within a given sequence above, the following
access wraps within the block.

7. For a burst length of one, A0-A8 (x16) select the

unique column to be accessed, and mode register
bit M3 is ignored.

Table 1

Burst Definition

Burst

Starting Column

Order of Accesses Within a Burst

Length

Address

Type = Sequential Type = Interleaved

0-1

1-0

A1 A0

0-1-2-3

1-2-3-0

1-0-3-2

2-3-0-1

3-0-1-2

3-2-1-0

A2 A1 A0

0-1-2-3-4-5-6-7

1-2-3-4-5-6-7-0

1-0-3-2-5-4-7-6

2-3-4-5-6-7-0-1

2-3-0-1-6-7-4-5

3-4-5-6-7-0-1-2

3-2-1-0-7-6-5-4

4-5-6-7-0-1-2-3

5-6-7-0-1-2-3-4

5-4-7-6-1-0-3-2

6-7-0-1-2-3-4-5

6-7-4-5-2-3-0-1

7-0-1-2-3-4-5-6

7-6-5-4-3-2-1-0

Full

n = A0-8

Cn, Cn + 1, Cn + 2

Page

Cn + 3, Cn + 4...

Not Supported

(y)

(location 0-y)

...Cn - 1,

Cn...

Figure 1

Mode Register Definition

Burst Type

Accesses within a given burst may be programmed

to be either sequential or interleaved; this is referred to
as the burst type and is selected via bit M3.

The ordering of accesses within a burst is deter-

mined by the burst length, the burst type and the start-
ing column address, as shown in Table 1.

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MOBILE SDRAM

PRELIMINARY

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

BANK,

COL b

OUT

n + 1

OUT

n + 2

OUT

n + 3

OUT

READ

X = 0 cycles

NOTE: Each READ command may be to either bank. DQM is LOW.

CAS Latency = 1

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

BANK,

COL b

OUT

n + 1

OUT

n + 2

OUT

n + 3

OUT

READ

X = 1 cycle

CAS Latency = 2

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

BANK,

COL b

OUT

n + 1

OUT

n + 2

OUT

n + 3

OUT

READ

NOP

X = 2 cycles

CAS Latency = 3

DON'T CARE

Reserved states should not be used as unknown

operation or incompatibility with future versions may
result.

Operating Mode

The normal operating mode is selected by setting

M7 and M8 to zero; the other combinations of values for
M7 and M8 are reserved for future use and/or test
modes. The programmed burst length applies to both
READ and WRITE bursts.

Test modes and reserved states should not be used

because unknown operation or incompatibility with
future versions may result.

Write Burst Mode

When M9 = 0, the burst length programmed via M0-

M2 applies to both READ and WRITE bursts; when M9
= 1, the programmed burst length applies to READ
bursts, but write accesses are single-location (nonburst)
accesses.

CAS Latency

The CAS latency is the delay, in clock cycles, be-

tween the registration of a READ command and the
availability of the first piece of output data. The la-
tency can be set to two or three clocks.

If a READ command is registered at clock edge n,

and the latency is m clocks, the data will be available by
clock edge n + m. The DQs will start driving as a result of
the clock edge one cycle earlier (n + m - 1), and provided
that the relevant access times are met, the data will be
valid by clock edge n + m. For example, assuming that
the clock cycle time is such that all relevant access times
are met, if a READ command is registered at T0 and the
latency is programmed to two clocks, the DQs will start
driving after T1 and the data will be valid by T2, as
shown in Figure 2. Table 2 below indicates the operat-
ing frequencies at which each CAS latency setting can
be used.

Figure 2

CAS Latency

Table 2

CAS Latency

ALLOWABLE OPERATING

FREQUENCY (MHz)

CAS

SPEED

LATENCY = 1 LATENCY = 2 LATENCY = 3

- 8

100

125

- 10

100

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MOBILE SDRAM

PRELIMINARY

EXTENDED MODE REGISTER

The Extended Mode Register controls the functions

beyond those controlled by the Mode Register. These
additional functions are special features of the Mobile
device. They include Temperature Compensated Self
Refresh (TCSR), Partial Array Self Refresh (PASR) and
Driver Strength.

The Extended Mode Register is programmed via

the Mode Register Set command (BA1=1,BA0=0) and
retains the stored information until it is programmed
again or the device loses power.

The Extended Mode Register must be programmed

with M6 through M12 set to "0." The Extended Mode
Register must be loaded when all banks are idle and no
bursts are in progress, and the controller must wait the
specified time before initiating any subsequent op-
eration. Violating these requirements results in un-
specified operation.

TEMPERATURE COMPENSATED SELF REFRESH

Temperature Compensated Self Refresh allows the

controller to program the Refresh interval during SELF
REFRESH mode, according to the case temperature of
the mobile device. This allows great power savings
during SELF REFRESH during most operating tempera-
ture ranges.

Every cell in the DRAM requires refreshing due to

the capacitor losing its charge over time. The refresh
rate is dependent on temperature. At higher tempera-
tures a capacitor loses charge quicker than at lower
temperatures, requiring the cells to be refreshed more
often. Historically, during Self Refresh, the refresh rate
has been set to accommodate the worst case, or highest
temperature range expected.

EXTENDED MODE REGISTER

Maximum Case Temp

A4 A3

A7 A6 A5 A4 A3

A2 A1 A0

Extended Mode
Register (Ex)

Address Bus

A10

A11

BA0

A12

PASR

TCSR

All have to be set to "0"

BA1

85°C

70°C

45°C

15°C

1 0

NOTE: 1. E14 and E13 (BA1 and BA0) must be "1, 0" to select the
Extended Mode Register (vs. the base Mode Register).

Self Refresh Coverage

Four Banks

Two Banks (BA1=0)

One Bank (BA1=BA0=0)

RFU

Half Bank (BA1=BA0=0)

Quarter Bank (BA1=BA0=0)

RFU

Driver Strength

Half Strength

Full Strength

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MOBILE SDRAM

PRELIMINARY

Thus, during ambiant temperatures, the power con-

sumed during refresh was unnecessarily high, because
the refresh rate was set to accommodate the higher
temperatures. Setting M4 and M3, allow the DRAM to
accomodate more specific temperature regions during
SELF REFRESH. There are four temperature settings,
which will vary the SELF REFRESH current according to
the selected temperature. This selectable refresh rate
will save power when the DRAM is operating at normal
temperatures.

PARTIAL ARRAY SELF REFRESH

For further power savings during SELF REFRESH,

the PASR feature allows the controller to select the
amount of memory that will be refreshed during SELF
REFRESH. The refresh options are four banks, two
banks (0 and 1), one bank (0), half bank (0 with internal
row address A12=0), and quarter bank (0 with internal
row address A12=0 and A11=0). WRITE and READ com-
mands can still occur during standard operation, but
only the selected banks will be refreshed during SELF
REFRESH. Data in banks that are disabled will be lost.

DEEP POWER DOWN

Deep Power Down is an operating mode to achieve

maximum power reduction by eliminating the power
of the whole memory array of the devices. Data will not
be retained once the device enters Deep Power Down
Mode.

This mode is entered by having all banks idle then /

CS and /WE held low with /RAS and /CAS held high at
the rising edge of the clock, while CKE is low. This mode
is exited by asserting CKE high.

DRIVER STRENGTH

Extended mode register bit A5 must be used to set

the DQ output drive strength. Full drive strength is
suitable for systems in which the SDRAM component
is placed on a module. Half drive strength is recom-
mended for point-to-point or other applications with
reduced output loading.

The half-strength can be used for point-to-point

applications. Point-to-point systems are usually lightly
loaded with a memory controller accessing one to eight
SDRAM components on the memory bus with module
stubs between these devices. Driver strength chosen
should be load dependent. The lighter the load, the
less driver strength that is needed for the outputs.

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MOBILE SDRAM

PRELIMINARY

TRUTH TABLE 1 COMMANDS AND DQM OPERATION

(Notes: 1)

NAME (FUNCTION)

CS# RAS# CAS# WE# DQM

ADDR

DQs

NOTES

COMMAND INHIBIT (NOP)

NO OPERATION (NOP)

ACTIVE (Select bank and activate row)

Bank/Row

READ (Select bank and column, and start READ burst) L

L/H

Bank/Col

WRITE (Select bank and column, and start WRITE burst) L

L/H

Bank/Col

Valid

DEEP POWER DOWN

PRECHARGE (Deactivate row in bank or banks)

Code

AUTO REFRESH or SELF REFRESH

6, 7

(Enter self refresh mode)

LOAD MODE REGISTER

Op-Code

Write Enable/Output Enable

Active

Write Inhibit/Output High-Z

High-Z

Truth Tables appear following the Operation section;
these tables provide current state/next state
information.

Commands

Truth Table 1 provides a quick reference of

available commands. This is followed by a written de-
scription of each command. Three additional

NOTE: 1. CKE is HIGH for all commands shown except SELF REFRESH.

2. A0-A11 define the op-code written to the mode register, and A12 should be driven LOW.
3. A0-A12 provide row address, and BA0, BA1 determine which bank is made active.
4. A0-A8 (x16)provide column address; A10 HIGH enables the auto precharge feature (nonpersistent), while A10 LOW

disables the auto precharge feature; BA0, BA1 determine which bank is being read from or written to.

5. A10 LOW: BA0, BA1 determine the bank being precharged. A10 HIGH: All banks precharged and BA0, BA1 are "Don't

Care."

6. This command is AUTO REFRESH if CKE is HIGH, SELF REFRESH if CKE is LOW.
7. Internal refresh counter controls row addressing; all inputs and I/Os are "Don't Care" except for CKE.
8. Activates or deactivates the DQs during WRITEs (zero-clock delay) and READs (two-clock delay).
9. Standard SDRAM parts assign this command sequence as Burst Terminate. For Mobile SDRAM parts, the Burst

Terminate command is assigned to the Deep Power Down function.

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MOBILE SDRAM

PRELIMINARY

COMMAND INHIBIT

The COMMAND INHIBIT function prevents new

commands from being executed by the SDRAM, re-
gardless of whether the CLK signal is enabled. The
SDRAM is effectively deselected. Operations already
in progress are not affected.

NO OPERATION (NOP)

The NO OPERATION (NOP) command is used to

perform a NOP to an SDRAM which is selected (CS# is
LOW). This prevents unwanted commands from being
registered during idle or wait states. Operations already
in progress are not affected.

LOAD MODE REGISTER

The mode register is loaded via inputs A0-A12 (A13

and A14 should be driven LOW to prevent Extended
Mode Register.) See mode register heading in the Reg-
ister Definition section. The LOAD MODE REGISTER
command can only be issued when all banks are idle,
and a subsequent executable command cannot be is-
sued until

MRD is met.

ACTIVE

The ACTIVE command is used to open (or activate)

a row in a particular bank for a subsequent access. The
value on the BA0, BA1 inputs selects the bank, and the
address provided on inputs A0-A12 selects the row.
This row remains active (or open) for accesses until a
PRECHARGE command is issued to that bank. A
PRECHARGE command must be issued before open-
ing a different row in the same bank.

READ

The READ command is used to initiate a burst read

access to an active row. The value on the BA0, BA1
inputs selects the bank, and the address provided on
inputs A0-A8 (x16) selects the starting column location.
The value on input A10 determines whether or not auto
precharge is used. If auto precharge is selected, the row
being accessed will be precharged at the end of the
READ burst; if auto precharge is not selected, the row
will remain open for subsequent accesses. Read data
appears on the DQs subject to the logic level on the
DQM inputs two clocks earlier. If a given DQM signal
was registered HIGH, the corresponding DQs will be
High-Z two clocks later; if the DQM signal was regis-
tered LOW, the DQs will provide valid data.

WRITE

The WRITE command is used to initiate a burst write

access to an active row. The value on the BA0, BA1
inputs selects the bank, and the address provided on

inputs A0-A8 (x16) selects the starting column location.
The value on input A10 determines whether or not
auto precharge is used. If auto precharge is selected,
the row being accessed will be precharged at the end of
the WRITE burst; if auto precharge is not selected, the
row will remain open for subsequent accesses. Input
data appearing on the DQs is written to the memory
array subject to the DQM input logic level appearing
coincident with the data. If a given DQM signal is regis-
tered LOW, the corresponding data will be written to
memory; if the DQM signal is registered HIGH, the
corresponding data inputs will be ignored, and a WRITE
will not be executed to that byte/column location.

PRECHARGE

The PRECHARGE command is used to deactivate

the open row in a particular bank or the open row in all
banks. The bank(s) will be available for a subsequent
row access a specified time (

RP) after the PRECHARGE

command is issued. Input A10 determines whether
one or all banks are to be precharged, and in the case
where only one bank is to be precharged, inputs BA0,
BA1 select the bank. Otherwise BA0, BA1 are treated as
"Don't Care." Once a bank has been precharged, it is in
the idle state and must be activated prior to any READ
or WRITE commands being issued to that bank.

AUTO PRECHARGE

Auto precharge is a feature which performs the

same individual-bank PRECHARGE function de-
scribed above, without requiring an explicit command.
This is accomplished by using A10 to enable auto
precharge in conjunction with a specific READ or WRITE
command. A PRECHARGE of the bank/row that is ad-
dressed with the READ or WRITE command is auto-
matically performed upon completion of the READ or
WRITE burst, except in the full-page burst mode, where
AUTO PRECHARGE does not apply. Auto precharge is
nonpersistent in that it is either enabled or disabled for
each individual READ or WRITE command.

Auto precharge ensures that the precharge is initi-

ated at the earliest valid stage within a burst. The user
must not issue another command to the same bank
until the precharge time (

RP) is completed. This is

determined as if an explicit PRECHARGE command
was issued at the earliest possible time, as described
for each burst type in the Operation section of this data
sheet.

AUTO REFRESH

AUTO REFRESH is used during normal operation of

the SDRAM and is analogous to CAS#-BEFORE-RAS#
(CBR) REFRESH in conventional DRAMs. This

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MOBILE SDRAM

PRELIMINARY

command is nonpersistent, so it must be issued each
time a refresh is required. All active banks must be
precharged prior to issuing an AUTO REFRESH com-
mand. The AUTO REFRESH command should not be
issued until the minimum

RP has been met after the

PRECHARGE command as shown in the operations sec-
tion.

The addressing is generated by the internal refresh

controller. This makes the address bits "Don't Care"
during an AUTO REFRESH command. The 256Mb
SDRAM requires 8,192 AUTO REFRESH cycles every
64ms (

REF), regardless of width option. Providing a

distributed AUTO REFRESH command every 7.81µs
will meet the refresh requirement and ensure that each
row is refreshed. Alternatively, 8,192 AUTO REFRESH
commands can be issued in a burst at the minimum
cycle rate (

RC), once every 64ms.

SELF REFRESH

The SELF REFRESH command can be used to retain

data in the SDRAM, even if the rest of the system is
powered down. When in the self refresh mode, the
SDRAM retains data without external clocking.

The SELF REFRESH command is initiated like an AUTO
REFRESH command except CKE is disabled (LOW).
Once the SELF REFRESH command is registered, all
the inputs to the SDRAM become "Don't Care" with
the exception of CKE, which must remain LOW.

Once self refresh mode is engaged, the SDRAM pro-

vides its own internal clocking, causing it to perform its
own AUTO REFRESH cycles. The SDRAM must remain
in self refresh mode for a minimum period equal to

RAS and may remain in self refresh mode for an indefi-

nite period beyond that.

The procedure for exiting self refresh requires a se-

quence of commands. First, CLK must be stable (stable
clock is defined as a signal cycling within timing con-
straints specified for the clock pin) prior to CKE going
back HIGH. Once CKE is HIGH, the SDRAM must have
NOP commands issued (a minimum of two clocks) for

XSR because time is required for the completion of any

internal refresh in progress.

Upon exiting the self refresh mode, AUTO REFRESH

commands must be issued every 7.81µs or less as both
SELF REFRESH and AUTO REFRESH utilize the row
refresh counter.

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MOBILE SDRAM

PRELIMINARY

CLK

COMMAND

NOP

ACTIVE

READ or

WRITE

NOP

RCD

DON'T CARE

Operation

BANK/ROW ACTIVATION

Before any READ or WRITE commands can be is-

sued to a bank within the SDRAM, a row in that bank
must be "opened." This is accomplished via the AC-
TIVE command, which selects both the bank and the
row to be activated (see Figure 3).

After opening a row (issuing an ACTIVE command),

a READ or WRITE command may be issued to that row,
subject to the

RCD specification.

RCD (MIN) should

be divided by the clock period and rounded up to the
next whole number to determine the earliest clock edge
after the ACTIVE command on which a READ or WRITE
command can be entered. For example, a

RCD specifi-

cation of 20ns with a 125 MHz clock (8ns period) results
in 2.5 clocks, rounded to 3. This is reflected in Figure 4,
which covers any case where 2 <

RCD (MIN)/

(The same procedure is used to convert other specifi-
cation limits from time units to clock cycles.)

A subsequent ACTIVE command to a different row

in the same bank can only be issued after the previous
active row has been "closed" (precharged). The mini-
mum time interval between successive ACTIVE com-
mands to the same bank is defined by

RC.

A subsequent ACTIVE command to another bank

can be issued while the first bank is being accessed,
which results in a reduction of total row-access over-
head. The minimum time interval between successive
ACTIVE commands to different banks is defined by

RRD.

Figure 4

Example: Meeting

RCD (MIN) When 2 <

RCD (MIN)/

CK <

< 3

Figure 3

Activating a Specific Row in a

Specific Bank

CS#

WE#

CAS#

RAS#

CKE

CLK

A0-A12

ROW

ADDRESS

DON'T CARE

HIGH

BA0, BA1

BANK

ADDRESS

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PRELIMINARY

CS#

WE#

CAS#

RAS#

CKE

CLK

COLUMN
ADDRESS

A0-A8: x16

A10

BA0,1

HIGH

ENABLE AUTO PRECHARGE

DISABLE AUTO PRECHARGE

BANK

ADDRESS

A9, A11: x16

Upon completion of a burst, assuming no other com-

mands have been initiated, the DQs will go High-Z. A
full-page burst will continue until terminated. (At the
end of the page, it will wrap to the start address and
continue.)

Data from any READ burst may be truncated with a

subsequent READ command, and data from a fixed-
length READ burst may be immediately followed by
data from a READ command. In either case, a continu-
ous flow of data can be maintained. The first data ele-
ment from the new burst follows either the last ele-
ment of a completed burst or the last desired data ele-
ment of a longer burst that is being truncated. The new
READ command should be issued x cycles before the
clock edge at which the last desired data element is
valid, where x equals the CAS latency minus one.

READs

READ bursts are initiated with a READ command,

as shown in Figure 5.

The starting column and bank addresses are pro-

vided with the READ command, and auto precharge is
either enabled or disabled for that burst access. If auto
precharge is enabled, the row being accessed is
precharged at the completion of the burst. For the ge-
neric READ commands used in the following illustra-
tions, auto precharge is disabled.

During READ bursts, the valid data-out element

from the starting column address will be available fol-
lowing the CAS latency after the READ command. Each
subsequent data-out element will be valid by the next
positive clock edge. Figure 6 shows general timing for
each possible CAS latency setting.

Figure 5

READ Command

Figure 6

CAS Latency

CLK

CAS Latency = 3

OUT

tOH

COMMAND

NOP

READ

tAC

NOP

DON'T CARE

UNDEFINED

CLK

CAS Latency = 1

OUT

tOH

COMMAND

NOP

READ

tAC

CLK

CAS Latency = 2

OUT

tOH

COMMAND

NOP

READ

tAC

NOP

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MOBILE SDRAM

PRELIMINARY

This is shown in Figure 7 for CAS latencies of two and
three; data element n + 3 is either the last of a burst of
four or the last desired of a longer burst. The 256Mb
SDRAM uses a pipelined architecture and therefore
does not require the 2n rule associated with a prefetch

Figure 7

Consecutive READ Bursts

architecture. A READ command can be initiated on any
clock cycle following a previous READ command. Full-
speed random read accesses can be performed to the
same bank, as shown in Figure 8, or each subsequent
READ may be performed to a different bank.

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

BANK,

COL b

OUT

n + 1

OUT

n + 2

OUT

n + 3

OUT

READ

X = 0 cycles

NOTE: Each READ command may be to either bank. DQM is LOW.

CAS Latency = 1

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

BANK,

COL b

OUT

n + 1

OUT

n + 2

OUT

n + 3

OUT

READ

X = 1 cycle

CAS Latency = 2

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

BANK,

COL b

OUT

n + 1

OUT

n + 2

OUT

n + 3

OUT

READ

NOP

X = 2 cycles

CAS Latency = 3

DON'T CARE

TRANSITIONING DATA

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DON'T CARE

READ

NOP

DQM

CLK

OUT

COMMAND

ADDRESS

BANK,

COL n

WRITE

BANK,

COL b

tHZ

NOTE:

A CAS latency of three is used for illustration. The READ command
may be to any bank, and the WRITE command may be to any bank.

TRANSITIONING DATA

DON'T CARE

READ

NOP

WRITE

NOP

CLK

DQM

OUT

COMMAND

ADDRESS

BANK,

COL n

BANK,

COL b

tHZ

tCK

NOTE:

A CAS latency of three is used for illustration. The READ
command may be to any bank, and the WRITE command
may be to any bank. If a burst of one is used, then DQM is
not required.

TRANSITIONING DATA

Data from any READ burst may be truncated with a

subsequent WRITE command, and data from a fixed-
length READ burst may be immediately followed by
data from a WRITE command (subject to bus turn-
around limitations). The WRITE burst may be initiated
on the clock edge immediately following the last (or last
desired) data element from the READ burst, provided
that I/O contention can be avoided. In a given system
design, there may be a possibility that the device driv-
ing the input data will go Low-Z before the SDRAM DQs
go High-Z. In this case, at least a single-cycle delay
should occur between the last read data and the WRITE
command.

The DQM input is used to avoid I/O contention, as

shown in Figures 9 and 10. The DQM signal must be
asserted (HIGH) at least two clocks prior to the WRITE
command (DQM latency is two clocks for output

buffers) to suppress data-out from the READ. Once the
WRITE command is registered, the DQs will go High-Z
(or remain High-Z), regardless of the state of the DQM
signal; provided the DQM was active on the clock just
prior to the WRITE command that truncated the READ
command. If not, the second WRITE will be an invalid
WRITE. For example, if DQM was LOW during T4 in
Figure 10, then the WRITEs at T5 and T7 would be
valid, while the WRITE at T6 would be invalid.

The DQM signal must be de-asserted prior to the

WRITE command (DQM latency is zero clocks for input
buffers) to ensure that the written data is not masked.
Figure 9 shows the case where the clock frequency al-
lows for bus contention to be avoided without adding a
NOP cycle, and Figure 10 shows the case where the
additional NOP is needed.

Figure 9

READ to WRITE

Figure 10

READ to WRITE With

Extra Clock Cycle

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Figure 11

READ to PRECHARGE

A fixed-length READ burst may be followed by, or

truncated with, a PRECHARGE command to the same
bank (provided that auto precharge was not acti-
vated), and a full-page burst may be truncated with a
PRECHARGE command to the same bank. The
PRECHARGE command should be issued x cycles be-
fore the clock edge at which the last desired data ele-
ment is valid, where x equals the CAS latency minus
one. This is shown in Figure 11 for each possible CAS
latency; data element n + 3 is either the last of a burst of

four or the last desired of a longer burst. Following the
PRECHARGE command, a subsequent command to
the same bank cannot be issued until

RP is met. Note

that part of the row precharge time is hidden during
the access of the last data element(s).

In the case of a fixed-length burst being executed to

CLK

OUT

COMMAND

ADDRESS

READ

NOP

OUT

n + 1

OUT

n + 2

OUT

n + 3

PRECHARGE

ACTIVE

t RP

NOTE: DQM is LOW.

CLK

OUT

COMMAND

ADDRESS

READ

NOP

OUT

n + 1

OUT

n + 2

OUT

n + 3

PRECHARGE

ACTIVE

t RP

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK a,

COL n

NOP

OUT

n + 1

OUT

n + 2

OUT

n + 3

PRECHARGE

ACTIVE

t RP

BANK a,

ROW

BANK

(a or all)

DON'T CARE

X = 0 cycles

CAS Latency = 1

X = 1 cycle

CAS Latency = 2

CAS Latency = 3

BANK a,

COL n

BANK a,

ROW

BANK

(a or all)

BANK a,

COL n

BANK a,

ROW

BANK

(a or all)

X = 2 cycles

TRANSITIONING DATA

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

Figure 12

Terminating a READ Burst

PRECHARGE command is that it requires that the com-
mand and address buses be available at the appropri-
ate time to issue the command; the advantage of the
PRECHARGE command is that it can be used to trun-
cate fixed-length or full-page bursts.

Full-page READ bursts can be truncated with the

BURST TERMINATE command, and fixed-length READ
bursts may be truncated with a BURST TERMINATE

command, provided that auto precharge was not acti-
vated. The BURST TERMINATE command should be
issued x cycles before the clock edge at which the last
desired data element is valid, where x equals the CAS
latency minus one. This is shown in Figure 12 for each
possible CAS latency; data element n + 3 is the last
desired data element of a longer burst.

DON'T CARE

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

OUT

n + 1

OUT

n + 2

OUT

n + 3

BURST

TERMINATE

NOP

NOTE: DQM is LOW.

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

OUT

n + 1

OUT

n + 2

OUT

n + 3

BURST

TERMINATE

NOP

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

OUT

n + 1

OUT

n + 2

OUT

n + 3

BURST

TERMINATE

NOP

X = 0 cycles

CAS Latency = 1

X = 1 cycle

CAS Latency = 2

CAS Latency = 3

X = 2 cycles

TRANSITIONING DATA

256Mb: x16 Mobile SDRAM

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

WRITEs

WRITE bursts are initiated with a WRITE command,

as shown in Figure 13.

The starting column and bank addresses are pro-

vided with the WRITE command, and auto precharge
is either enabled or disabled for that access. If auto
precharge is enabled, the row being accessed is
precharged at the completion of the burst. For the ge-
neric WRITE commands used in the following illustra-
tions, auto precharge is disabled.

During WRITE bursts, the first valid data-in ele-

ment will be registered coincident with the WRITE com-
mand. Subsequent data elements will be registered on
each successive positive clock edge. Upon completion
of a fixed-length burst, assuming no other commands
have been initiated, the DQs will remain High-Z and
any additional input data will be ignored (see Figure
14). A full-page burst will continue until terminated.
(At the end of the page, it will wrap to the start address
and continue.)

Data for any WRITE burst may be truncated with a

subsequent WRITE command, and data for a fixed-
length WRITE burst may be immediately followed by
data for a WRITE command. The new WRITE command
can be issued on any clock following the previous WRITE
command, and the data provided coincident with the
new command applies to the new command. An ex-

Figure 15

WRITE to WRITE

ample is shown in Figure 15. Data n + 1 is either the last
of a burst of two or the last desired of a longer burst. The
256Mb SDRAM uses a pipelined architecture and there-
fore does not require the 2n rule associated with a
prefetch architecture. A WRITE command can be initi-
ated on any clock cycle following a previous WRITE
command. Full-speed random write accesses within a
page can be performed to the same bank, as shown in
Figure 16, or each subsequent WRITE may be per-
formed to a different bank.

CLK

COMMAND

ADDRESS

NOP

WRITE

n + 1

NOP

BANK,

COL n

Figure 14

WRITE Burst

CLK

COMMAND

ADDRESS

NOP

WRITE

BANK,

COL n

BANK,

COL b

n + 1

NOTE: DQM is LOW. Each WRITE command may

be to any bank.

DON'T CARE

TRANSITIONING DATA

Figure 13

WRITE Command

CS#

WE#

CAS#

RAS#

CKE

CLK

COLUMN
ADDRESS

HIGH

ENABLE AUTO PRECHARGE

DISABLE AUTO PRECHARGE

BANK

ADDRESS

A0-A8: x16

A10

BA0,1

A9, A11: x16

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

requires a

WR of at least one clock plus time, regardless

of frequency. In addition, when truncating a WRITE
burst, the DQM signal must be used to mask input data
for the clock edge prior to, and the clock edge coinci-
dent with, the PRECHARGE command. An example is
shown in Figure 18. Data n + 1 is either the last of a burst
of two or the last desired of a longer burst. Following the
PRECHARGE command, a subsequent command to
the same bank cannot be issued until

RP is met. The

precharge can be issued coincident with the first coin-
cident clock edge (T2 in Figure 18) on an A1 Version and
with the second clock on an A2 Version (Figure 18.)

In the case of a fixed-length burst being executed to

completion, a PRECHARGE command issued at the
optimum time (as described above) provides the same
operation that would result from the same fixed-length
burst with auto precharge. The disadvantage of the
PRECHARGE command is that it requires that the com-
mand and address buses be available at the appropri-
ate time to issue the command; the advantage of the
PRECHARGE command is that it can be used to trun-
cate fixed-length or full-page bursts.

Figure 18

WRITE to PRECHARGE

DON'T CARE

DQM

CLK

COMMAND

ADDRESS

BANK a,

COL n

NOP

WRITE

PRECHARGE

NOP

n + 1

ACTIVE

t RP

BANK

(a or all)

t WR

BANK a,

ROW

DQM

COMMAND

ADDRESS

BANK a,

COL n

NOP

WRITE

PRECHARGE

NOP

n + 1

ACTIVE

t RP

BANK

(a or all)

t WR

NOTE: DQM could remain LOW in this example if the WRITE burst is a fixed length of two.

BANK a,

ROW

NOP

tWR @ tCLK 15ns

tWR = tCLK < 15ns

TRANSITIONING DATA

Data for any WRITE burst may be truncated with a

subsequent READ command, and data for a fixed-
length WRITE burst may be immediately followed by a
READ command. Once the READ command is regis-
tered, the data inputs will be ignored, and WRITEs will
not be executed. An example is shown in Figure 17.
Data n + 1 is either the last of a burst of two or the last
desired of a longer burst.

Data for a fixed-length WRITE burst may be fol-

lowed by, or truncated with, a PRECHARGE command
to the same bank (provided that auto precharge was
not activated), and a full-page WRITE burst may be
truncated with a PRECHARGE command to the same
bank. The PRECHARGE command should be issued

WR after the clock edge at which the last desired input

data element is registered. The auto precharge mode

Figure 17

WRITE to READ

DON'T CARE

CLK

COMMAND

ADDRESS

NOP

WRITE

BANK,

COL n

n + 1

OUT

READ

NOP

BANK,

COL b

NOP

OUT

b + 1

NOTE:

The WRITE command may be to any bank, and the READ command
may be to any bank. DQM is LOW. CAS latency = 2 for illustration.

TRANSITIONING DATA

Figure 16

Random WRITE Cycles

DON'T CARE

CLK

COMMAND

ADDRESS

WRITE

BANK,

COL n

WRITE

BANK,

COL a

BANK,

COL x

BANK,
COL m

NOTE: Each WRITE command may be to any bank. DQM is LOW.

TRANSITIONING DATA

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

Fixed-length or full-page WRITE bursts can be trun-

cated with the BURST TERMINATE command. When
truncating a WRITE burst, the input data applied coin-
cident with the BURST TERMINATE command will be
ignored. The last data written (provided that DQM is
LOW at that time) will be the input data applied one
clock previous to the BURST TERMINATE command.
This is shown in Figure 19, where data n is the last
desired data element of a longer burst.

Figure 21

Power-Down

DON'T CARE

tRAS

tRCD

tRC

All banks idle

Input buffers gated off

Exit power-down mode.

(

)

(

)

(

)

(

)

(

)

(

)

tCKS

> tCKS

COMMAND

NOP

ACTIVE

Enter power-down mode.

NOP

CLK

CKE

(

)

(

)

(

)

(

)

Figure 20

PRECHARGE Command

Figure 19

Terminating a WRITE Burst

DON'T CARE

TRANSITIONING DATA

CLK

COMMAND

ADDRESS

BANK,

COL n

WRITE

BURST

TERMINATE

COMMAND

(ADDRESS)

(DATA)

NOTE: DQMs are LOW.

PRECHARGE

The PRECHARGE command (see Figure 20) is used

to deactivate the open row in a particular bank or the
open row in all banks. The bank(s) will be available for
a subsequent row access some specified time (

RP) af-

ter the PRECHARGE command is issued. Input A10
determines whether one or all banks are to be
precharged, and in the case where only one bank is to
be precharged, inputs BA0, BA1 select the bank. When
all banks are to be precharged, inputs BA0, BA1 are
treated as "Don't Care." Once a bank has been
precharged, it is in the idle state and must be activated
prior to any READ or WRITE commands being issued to
that bank.

POWER-DOWN

Power-down occurs if CKE is registered LOW coinci-

dent with a NOP or COMMAND INHIBIT when no ac-
cesses are in progress. If power-down occurs when all
banks are idle, this mode is referred to as precharge
power-down; if power-down occurs when there is a row
active in any bank, this mode is referred to as active
power-down. Entering power-down deactivates the in-
put and output buffers, excluding CKE, for maximum
power savings while in standby. CKE must be held low
during power down. The device may not remain in the
power-down state longer than the refresh period
(64ms) since no refresh operations are performed in
this mode.

The power-down state is exited by registering a NOP

or COMMAND INHIBIT and CKE HIGH at the desired
clock edge (meeting

CKS). See Figure 21.

DON'T CARE

CS#

WE#

CAS#

RAS#

CKE

CLK

A10

HIGH

All Banks

Bank Selected

A0-A9, A11, A12

BA0, BA1

BANK

ADDRESS

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

DON'T CARE

COMMAND

ADDRESS

WRITE

BANK,

COL n

NOP

CLK

CKE

INTERNAL

CLOCK

NOP

n + 1

n + 2

NOTE: For this example, burst length = 4 or greater, and DM

is LOW.

TRANSITIONING DATA

Figure 22

Clock Suspend During WRITE Burst

CLOCK SUSPEND

The clock suspend mode occurs when a column ac-

cess/burst is in progress and CKE is registered LOW. In
the clock suspend mode, the internal clock is deacti-
vated, "freezing" the synchronous logic.

For each positive clock edge on which CKE is

sampled LOW, the next internal positive clock edge is
suspended. Any command or data present on the in-
put pins at the time of a suspended internal clock edge
is ignored; any data present on the DQ pins remains
driven; and burst counters are not incremented, as
long as the clock is suspended. (See examples in Fig-
ures 22 and 23.)

Clock suspend mode is exited by registering CKE

HIGH; the internal clock and related operation will re-
sume on the subsequent positive clock edge.

DEEP POWER-DOWN

Deep Power Down mode is a maximum power sav-

ings feature achieved by shutting off the power to the
entire memory array of the device. Data will not be
retained once Deep Power Down mode is executed.
Deep Power Down mode is entered by having all banks
idle then /CS and /WE held low with /RAS and /CAS
high at the rising edge of the clock, while CKE is low.
CKE must be held low during Deep Power Down.

In order to exit Deep Power Down mode, CKE must

be asserted high. After exiting, the following sequence
is needed in order to enter a new command. Maintain
NOP input conditions for a minimum of 200us. Issue
PRECHARGE commands for all banks. Issue eight or
more AUTOREFRESH commands. Issue a MODE REG-
ISTER set command to initialize mode register. Issue
a EXTENDED MODE REGISTER set command to ini-
tialize the extended mode register. See Figure 21A.

Figure 21A

Deep Power-Down

DON T CARE

Exit deep power-down mode.

(

)

(

)

(

)

(

)

Enter deep power-down mode.

CLK

CKE

CS#

WE#

CAS#

RAS#

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

DON'T CARE

CLK

OUT

COMMAND

ADDRESS

READ

NOP

BANK,

COL n

NOP

OUT

n + 1

OUT

n + 2

OUT

n + 3

NOTE: For this example, CAS latency = 2, burst length = 4 or greater, and

DQM is LOW.

CKE

INTERNAL

CLOCK

NOP

TRANSITIONING DATA

Figure 23

Clock Suspend During READ Burst

BURST READ/SINGLE WRITE

The burst read/single write mode is entered by pro-

gramming the write burst mode bit (M9) in the mode
register to a logic 1. In this mode, all WRITE commands
result in the access of a single column location (burst of
one), regardless of the programmed burst length. READ
commands access columns according to the pro-
grammed burst length and sequence, just as in the
normal mode of operation (M9 = 0).

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

CONCURRENT AUTO PRECHARGE

An access command (READ or WRITE) to another

bank while an access command with auto precharge
enabled is executing is not allowed by SDRAMs,
unless the SDRAM supports CONCURRENT AUTO
PRECHARGE. Micron SDRAMs support CONCURRENT
AUTO PRECHARGE. Four cases where CONCURRENT
AUTO PRECHARGE occurs are defined below.

READ with Auto Precharge
1. Interrupted by a READ (with or without auto

precharge): A READ to bank m will interrupt a READ

on bank n, CAS latency later. The PRECHARGE to
bank n will begin when the READ to bank m is regis-
tered (Figure 24).

2. Interrupted by a WRITE (with or without auto

precharge): A WRITE to bank m will interrupt a READ
on bank n when registered. DQM should be used
two clocks prior to the WRITE command to prevent
bus contention. The PRECHARGE to bank n will
begin when the WRITE to bank m is registered (Fig-
ure 25).

DON'T CARE

CLK

OUT

COMMAND

READ - AP

BANK n

NOP

OUT

a + 1

OUT

d + 1

NOP

BANK n

CAS Latency = 3 (BANK m)

BANK m

ADDRESS

Idle

NOP

NOTE: DQM is LOW.

BANK n,

COL a

BANK m,

COL d

READ - AP

BANK m

Internal
States

Page Active

READ with Burst of 4

Interrupt Burst, Precharge

Page Active

READ with Burst of 4

Precharge

RP - BANK n

tRP - BANK m

CAS Latency = 3 (BANK n)

TRANSITIONING DATA

Figure 24

READ With Auto Precharge Interrupted by a READ

CLK

OUT

COMMAND

NOP

d + 1

d + 2

d + 3

NOP

BANK n

BANK m

ADDRESS

Idle

NOP

DQM

NOTE: 1. DQM is HIGH at T2 to prevent D

OUT

-a+1 from contending with D

-d at T4.

BANK n,

COL a

BANK m,

COL d

WRITE - AP

BANK m

Internal
States

Page

Active

READ with Burst of 4

Interrupt Burst, Precharge

Page Active

WRITE with Burst of 4

Write-Back

RP - BANK n

t WR - BANK m

CAS Latency = 3 (BANK n)

READ - AP

BANK n

DON'T CARE

TRANSITIONING DATA

Figure 25

READ With Auto Precharge Interrupted by a WRITE

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MOBILE SDRAM

PRELIMINARY

DON'T CARE

CLK

COMMAND

WRITE - AP

BANK n

NOP

a + 1

NOP

BANK n

BANK m

ADDRESS

NOTE: 1. DQM is LOW.

BANK n,

COL a

BANK m,

COL d

READ - AP

BANK m

Internal
States

Page Active

WRITE with Burst of 4

Interrupt Burst, Write-Back

Precharge

Page Active

READ with Burst of 4

tRP - BANK m

OUT

d + 1

CAS Latency = 3 (BANK m)

RP - BANK n

WR - BANK n

TRANSITIONING DATA

Figure 26

WRITE With Auto Precharge Interrupted by a READ

DON'T CARE

CLK

COMMAND

WRITE - AP

BANK n

NOP

d + 1

a + 1

a + 2

d + 2

d + 3

NOP

BANK n

BANK m

ADDRESS

NOP

NOTE: 1. DQM is LOW.

BANK n,

COL a

BANK m,

COL d

WRITE - AP

BANK m

Internal
States

Page Active

WRITE with Burst of 4

Interrupt Burst, Write-Back

Precharge

Page Active

WRITE with Burst of 4

Write-Back

WR - BANK n

tRP - BANK n

t WR - BANK m

TRANSITIONING DATA

Figure 27

WRITE With Auto Precharge Interrupted by a WRITE

WRITE with Auto Precharge
3. Interrupted by a READ (with or without auto

precharge): A READ to bank m will interrupt a WRITE
on bank n when registered, with the data-out ap-
pearing CAS latency later. The PRECHARGE to bank
n will begin after

WR is met, where

WR begins when

the READ to bank m is registered. The last valid
WRITE to bank n will be data-in registered one clock
prior to the READ to bank m (Figure 26).

4. Interrupted by a WRITE (with or without auto

precharge): A WRITE to bank m will interrupt a
WRITE on bank n when registered. The
PRECHARGE to bank n will begin after

WR is met,

where

WR begins when the WRITE to bank m is

registered. The last valid data WRITE to bank n will
be data registered one clock prior to a WRITE to
bank m (Figure 27).

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

TRUTH TABLE 2 CKE

(Notes: 1-4)

CKE

n-1

CKE

CURRENT STATE

COMMAND

ACTION

NOTES

Power-Down

Maintain Power-Down

Self Refresh

Maintain Self Refresh

Clock Suspend

Maintain Clock Suspend

Power-Down

COMMAND INHIBIT or NOP

Exit Power-Down

Deep Power-Down

Exit Deep Power-Down

Self Refresh

COMMAND INHIBIT or NOP

Exit Self Refresh

Clock Suspend

Exit Clock Suspend

All Banks Idle

COMMAND INHIBIT or NOP

Power-Down Entry

All Banks Idle

DEEP POWER DOWN

Deep Power-Down Entry

All Banks Idle

AUTO REFRESH

Self Refresh Entry

Reading or Writing

VALID

Clock Suspend Entry

See Truth Table 3

NOTE: 1. CKE

is the logic state of CKE at clock edge n; CKE

n-1

was the state of CKE at the previous clock edge.

2. Current state is the state of the SDRAM immediately prior to clock edge n.
3. COMMAND

is the command registered at clock edge n, and ACTION

is a result of COMMAND

4. All states and sequences not shown are illegal or reserved.
5. Exiting power-down at clock edge n will put the device in the all banks idle state in time for clock edge n + 1 (provided

that

CKS is met).

6. Exiting self refresh at clock edge n will put the device in the all banks idle state once

XSR is met. COMMAND INHIBIT

or NOP commands should be issued on any clock edges occurring during the

XSR period. A minimum of two NOP

commands must be provided during

XSR period.

7. After exiting clock suspend at clock edge n, the device will resume operation and recognize the next command at clock

edge n + 1.

8. Deep Power-Down is a power savings feature of this Mobile SDRAM device. This command is Burst Terminate on

traditional SDRAM components. For Mobile SDRAM devices, this command sequence is assigned to Deep Power Down.

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

TRUTH TABLE 3 CURRENT STATE BANK n, COMMAND TO BANK n

(Notes: 1-6; notes appear below and on next page)

CURRENT STATE

CS# RAS# CAS# WE#

COMMAND (ACTION)

NOTES

Any

COMMAND INHIBIT (NOP/Continue previous operation)

NO OPERATION (NOP/Continue previous operation)

ACTIVE (Select and activate row)

Idle

AUTO REFRESH

LOAD MODE REGISTER

PRECHARGE

READ (Select column and start READ burst)

Row Active

WRITE (Select column and start WRITE burst)

PRECHARGE (Deactivate row in bank or banks)

Read

READ (Select column and start new READ burst)

(Auto

WRITE (Select column and start WRITE burst)

Precharge

PRECHARGE (Truncate READ burst, start PRECHARGE)

Disabled)

DEEP POWER DOWN

Write

READ (Select column and start READ burst)

(Auto

WRITE (Select column and start new WRITE burst)

Precharge

PRECHARGE (Truncate WRITE burst, start PRECHARGE)

Disabled)

DEEP POWER DOWN

NOTE: 1. This table applies when CKE

n-1

was HIGH and CKE

is HIGH (see Truth Table 2) and after

XSR has been

met (if the previous state was self refresh).

2. This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown

are those allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.

3. Current state definitions:

Idle: The bank has been precharged, and

RP has been met.

Row Active: A row in the bank has been activated, and

RCD has been met. No data bursts/accesses and no

Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated or

been terminated.

Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated

or been terminated.

4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT or NOP

commands, or allowable commands to the other bank should be issued on any clock edge occurring during these states.
Allowable commands to the other bank are determined by its current state and Truth Table 3, and according to Truth
Table 4.

Precharging: Starts with registration of a PRECHARGE command and ends when

RP is met. Once

RP is met,

the bank will be in the idle state.

Row Activating: Starts with registration of an ACTIVE command and ends when

RCD is met. Once

RCD is met,

the bank will be in the row active state.

Read w/Auto

Precharge Enabled: Starts with registration of a READ command with auto precharge enabled and ends when

has been met. Once

RP is met, the bank will be in the idle state.

Write w/Auto

Precharge Enabled: Starts with registration of a WRITE command with auto precharge enabled and ends when

has been met. Once

RP is met, the bank will be in the idle state.

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

NOTE (continued):

5. The following states must not be interrupted by any executable command; COMMAND INHIBIT or NOP commands must

be applied on each positive clock edge during these states.

Refreshing: Starts with registration of an AUTO REFRESH command and ends when

RC is met. Once

RC is

met, the SDRAM will be in the all banks idle state.

Accessing Mode

MRD has been

met. Once

MRD is met, the SDRAM will be in the all banks idle state.

Precharging All: Starts with registration of a PRECHARGE ALL command and ends when

RP is met. Once

RP is

met, all banks will be in the idle state.

6. All states and sequences not shown are illegal or reserved.
7. Not bank-specific; requires that all banks are idle.
8. May or may not be bank-specific; if all banks are to be precharged, all must be in a valid state for precharging.
9. Deep Power-Down is a power savings feature of this Mobile SDRAM device. This command is Burst Terminate on

traditional SDRAM components. For Mobile SDRAM devices, this command sequence is assigned to Deep Power Down.

10. READs or WRITEs listed in the Command (Action) column include READs or WRITEs with auto precharge enabled and

READs or WRITEs with auto precharge disabled.

11. Does not affect the state of the bank and acts as a NOP to that bank.

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

TRUTH TABLE 4 CURRENT STATE BANK n, COMMAND TO BANK m

(Notes: 1-6; notes appear on next page)

CURRENT STATE

CS# RAS# CAS# WE#

COMMAND (ACTION)

NOTES

Any

COMMAND INHIBIT (NOP/Continue previous operation)

NO OPERATION (NOP/Continue previous operation)

Idle

Any Command Otherwise Allowed to Bank m

Row

ACTIVE (Select and activate row)

Activating,

READ (Select column and start READ burst)

Active, or

WRITE (Select column and start WRITE burst)

Precharging

PRECHARGE

Read

ACTIVE (Select and activate row)

(Auto

READ (Select column and start new READ burst)

7, 10

Precharge

WRITE (Select column and start WRITE burst)

7, 11

Disabled)

PRECHARGE

Write

ACTIVE (Select and activate row)

(Auto

READ (Select column and start READ burst)

7, 12

Precharge

WRITE (Select column and start new WRITE burst)

7, 13

Disabled)

PRECHARGE

Read

ACTIVE (Select and activate row)

(With Auto

READ (Select column and start new READ burst)

7, 8, 14

Precharge)

WRITE (Select column and start WRITE burst)

7, 8, 15

PRECHARGE

Write

ACTIVE (Select and activate row)

(With Auto

READ (Select column and start READ burst)

7, 8, 16

Precharge)

WRITE (Select column and start new WRITE burst)

7, 8, 17

PRECHARGE

NOTE: 1. This table applies when CKE

n-1

was HIGH and CKE

is HIGH (see Truth Table 2) and after

XSR has been met (if the

previous state was self refresh).

2. This table describes alternate bank operation, except where noted; i.e., the current state is for bank n and the

commands shown are those allowed to be issued to bank m (assuming that bank m is in such a state that the given
command is allowable). Exceptions are covered in the notes below.

3. Current state definitions:

Idle: The bank has been precharged, and

RP has been met.

Row Active: A row in the bank has been activated, and

RCD has been met. No data bursts/accesses and no

Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated or

been terminated.

Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated

or been terminated.

Read w/Auto

Precharge Enabled: Starts with registration of a READ command with auto precharge enabled, and ends when

has been met. Once

RP is met, the bank will be in the idle state.

Write w/Auto

Precharge Enabled: Starts with registration of a WRITE command with auto precharge enabled, and ends when

has been met. Once

RP is met, the bank will be in the idle state.

256Mb: x16 Mobile SDRAM

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MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

NOTE: (continued)

4. AUTO REFRESH, SELF REFRESH and LOAD MODE REGISTER commands may only be issued when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state

only.

6. All states and sequences not shown are illegal or reserved.
7. READs or WRITEs to bank m listed in the Command (Action) column include READs or WRITEs with auto precharge

enabled and READs or WRITEs with auto precharge disabled.

8. CONCURRENT AUTO PRECHARGE: Bank n will initiate the auto precharge command when its burst has been interrupted

by bank m's burst.

9. Burst in bank n continues as initiated.

10. For a READ without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will

interrupt the READ on bank n, CAS latency later (Figure 7).

11. For a READ without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will

interrupt the READ on bank n when registered (Figures 9 and 10). DQM should be used one clock prior to the WRITE
command to prevent bus contention.

12. For a WRITE without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will

interrupt the WRITE on bank n when registered (Figure 17), with the data-out appearing CAS latency later. The last
valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m.

13. For a WRITE without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m

will interrupt the WRITE on bank n when registered (Figure 15). The last valid WRITE to bank n will be data-in
registered one clock prior to the READ to bank m.

14. For a READ with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will

interrupt the READ on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is
registered (Figure 24).

15. For a READ with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will

interrupt the READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to prevent
bus contention. The PRECHARGE to bank n will begin when the WRITE to bank m is registered (Figure 25).

16. For a WRITE with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will

interrupt the WRITE on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to bank
n will begin after

WR is met, where

WR begins when the READ to bank m is registered. The last valid WRITE to bank n

will be data-in registered one clock prior to the READ to bank m (Figure 26).

17. For a WRITE with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will

interrupt the WRITE on bank n when registered. The PRECHARGE to bank n will begin after

WR is met, where

begins when the WRITE to bank m is registered. The last valid WRITE to bank n will be data registered one clock prior
to the WRITE to bank m (Figure 27).

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS - V version

(Notes: 1, 5, 6; notes appear on page 40; V

= +2.5V ±0.2V V

Q = +2.5V ±0.2V or V

Q = +1.8V ±0.15V)

PARAMETER/CONDITION

SYMBOL

MIN

MAX

UNITS NOTES

SUPPLY VOLTAGE

2.3

2.7

I/O SUPPLY VOLTAGE

DDQ

1.65

2.7

INPUT HIGH VOLTAGE: Logic 1; All inputs

0.8 * V

Q V

Q + 0.3

INPUT LOW VOLTAGE: Logic 0; All inputs

-0.3

0.3

DATA OUTPUT HIGH VOLTAGE: Logic 1; All inputs

Q - 0.2

DATA OUTPUT LOW VOLTAGE: LOGIC 0; All inputs

0.2

INPUT LEAKAGE CURRENT:

-5

µA

Any input 0V

(All other pins not under test = 0V)

OUTPUT LEAKAGE CURRENT: DQs are disabled; 0V

OUT

-5

µA

ABSOLUTE MAXIMUM RATINGS*

Voltage on V

Q Supply

Relative to V

(3.3V) ........................ -1V to +4.6V

Relative to V

(2.5V) ..................... -0.5V to +3.6V

Relative to V

(1.8V) .................. -0.35V to +2.8V

Voltage on Inputs, NC or I/O Pins

Relative to V

(3.3V) ........................ -1V to +4.6V

Relative to V

(2.5V) ..................... -0.5V to +3.6V

Relative to V

(1.8V) .................. -0.35V to +2.8V

Operating Temperature,

(commercial) ..................................... 0°C to +70°C

(industrial; IT parts) .................... -40°C to +85°C

Storage Temperature (plastic) ............ -55°C to +150°C
Power Dissipation ........................................................ 1 W

*Stresses greater than those listed under "Absolute
Maximum Ratings" may cause permanent damage to
the device. This is a stress rating only, and functional
operation of the device at these or any other conditions
above those indicated in the operational sections of
this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may
affect reliability.

DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS - LC version

(Notes: 1, 5, 6; notes appear on page 40; V

Q = 3.3 ±0.3V)

PARAMETER/CONDITION

SYMBOL

MIN

MAX

UNITS NOTES

SUPPLY VOLTAGE

3.6

I/O SUPPLY VOLTAGE

DDQ

3.6

INPUT HIGH VOLTAGE: Logic 1; All inputs

Q + 0.3

INPUT LOW VOLTAGE: Logic 0; All inputs

-0.3

0.8

DATA OUTPUT HIGH VOLTAGE: Logic 1; All inputs

2.4

DATA OUTPUT LOW VOLTAGE: LOGIC 0; All inputs

0.4

INPUT LEAKAGE CURRENT:

-5

µA

Any input 0V

(All other pins not under test = 0V)

OUTPUT LEAKAGE CURRENT: DQs are disabled; 0V

OUT

-5

µA

256Mb: x16 Mobile SDRAM

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MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS - H version

(Notes: 1, 5, 6; notes appear on page 40; V

= 1.8 ±0.15V, V

DDQ

= +1.8V ±0.15V )

PARAMETER/CONDITION

SYMBOL

MIN

MAX

UNITS NOTES

SUPPLY VOLTAGE

1.65

1.95

I/O SUPPLY VOLTAGE

DDQ

1.65

1.95

INPUT HIGH VOLTAGE: Logic 1; All inputs

0.8*V

Q V

Q + 0.3

INPUT LOW VOLTAGE: Logic 0; All inputs

-0.3

0.3

DATA OUTPUT HIGH VOLTAGE: Logic 1; All inputs

Q -0.2

DATA OUTPUT LOW VOLTAGE: LOGIC 0; All inputs

0.2

INPUT LEAKAGE CURRENT:

-5

µA

Any input 0V

(All other pins not under test = 0V)

OUTPUT LEAKAGE CURRENT: DQs are disabled; 0V

OUT

-5

µA

CAPACITANCE FBGA

(Note: 2; notes appear on page 40)

PARAMETER

SYMBOL

MIN

M A X

UNITS NOTES

Input Capacitance: CLK

1.5

4.0

p F

Input Capacitance: All other input-only pins

1.5

4.0

p F

Input/Output Capacitance: DQs

3.0

6.0

p F

CAPACITANCE TSOP

(Note: 2; notes appear on page 40)

PARAMETER

SYMBOL

MIN

M A X

UNITS NOTES

Input Capacitance: CLK

2.5

4.0

p F

Input Capacitance: All other input-only pins

2.5

4.0

p F

Input/Output Capacitance: DQs

4.0

6.0

p F

256Mb: x16 Mobile SDRAM

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MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

ELECTRICAL CHARACTERISTICS AND RECOMMENDED AC OPERATING CONDITIONS

(Notes: 5, 6, 8, 9, 11; notes appear on page 40)

AC CHARACTERISTICS

-8

-10

PARAMETER

SYMBOL MIN

MAX

MIN

MAX UNITS NOTES

Access time from CLK (pos. edge)

CL = 3

AC(3)

CL = 2

AC(2)

CL = 1

AC(1)

Address hold time

Address setup time

2.5

CLK high-level width

CLK low-level width

Clock cycle time

CL = 3

CK(3)

CL = 2

CK(2)

CL = 1

CK(1)

CKE hold time

CKH

CKE setup time

CKS

2.5

CS#, RAS#, CAS#, WE#, DQM hold time

CMH

CS#, RAS#, CAS#, WE#, DQM setup time

CMS

2.5

Data-in hold time

Data-in setup time

2.5

Data-out high-impedance time

CL = 3

HZ(3)

CL = 2

HZ(2)

CL = 1

HZ(1)

Data-out low-impedance time

Data-out hold time (load)

2.5

Data-out hold time (no load)

1.8

ACTIVE to PRECHARGE command

RAS

120,000

ACTIVE to ACTIVE command period

100

28E

ACTIVE to READ or WRITE delay

RCD

Refresh period (8,192 rows)

REF

AUTO REFRESH period

RFC

100

28E

PRECHARGE cmd period

ACTIVE bank a to bank b command

RRD

Transition time

0.5

1.2

0.5

1.2

WRITE recovery time

1CLK+

7ns

5ns

28E

Exit SELF REFRESH to ACTIVE command

XSR

100

28E

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256Mb: x16

MOBILE SDRAM

PRELIMINARY

AC FUNCTIONAL CHARACTERISTICS

(Notes: 5, 6, 7, 8, 9, 11; notes appear on page 40)

PARAMETER

SYMBOL

-8

-10

UNITS NOTES

READ/WRITE command to READ/WRITE command

CCD

CKE to clock disable or power-down entry mode

CKED

CKE to clock enable or power-down exit setup mode

PED

DQM to input data delay

DQD

DQM to data mask during WRITEs

DQM

DQM to data high-impedance during READs

DQZ

WRITE command to input data delay

DWD

Data-in to ACTIVE command

DAL

15, 21

Data-in to PRECHARGE command

DPL

16, 21

Last data-in to burst STOP command

BDL

Last data-in to new READ/WRITE command

CDL

Last data-in to PRECHARGE command

RDL

16, 21

LOAD MODE REGISTER command to ACTIVE or REFRESH command

MRD

Data-out to high-impedance from PRECHARGE command

CL = 3

ROH(3)

CL = 2

ROH(2)

CL = 1

ROH(1)

256Mb: x16 Mobile SDRAM

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MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

- SELF REFRESH CURRENT OPTIONS (Temperature Compensated Self Refresh)

(Notes: 1, 6, 11, 13; notes appear on page 40)V

Q = 3.3 ±0.3V or V

Q = 2.5V ±0.2V or

Q = 1.8V ±0.15V)

Temperature Compensated Self Refresh

Max

-8

-10

UNITS

NOTES

Parameter/Condition

Temperature

Self Refresh Current: CKE < 0.2V

85°C

750

µA

45°C

500

µA

SPECIFICATIONS AND CONDITIONS

(Notes: 1, 5, 6, 11, 13; notes appear on page 40; V

Q = 3.3 ±0.3V; V

= 2.5V ±0.2V V

Q = 2.5V ±0.2V or

Q = 1.8V ±0.2V)

PARAMETER/CONDITION

S Y M B O L

- 8

- 1 0 U N I T S N O T E S

OPERATING CURRENT: Active Mode;

3, 18,

Burst = 2; READ or WRITE;

RC =

RC (MIN)

19, 32

STANDBY CURRENT: Power-Down Mode;

500

µA

All banks idle; CKE = LOW

STANDBY CURRENT: Active Mode; CKE = HIGH; CS# = HIGH;

3, 12,

All banks active after

RCD met; No accesses in progress

19, 32

OPERATING CURRENT: Burst Mode; Continuous burst;

105

3, 18,

READ or WRITE; All banks active

19, 32

AUTO REFRESH CURRENT

RFC =

RFC (MIN)

165

155

3, 12,

CKE = HIGH; CS# = HIGH

18, 19,

RFC = 7.8µs

2.5

32, 33

DEEP POWER DOWN

µA

MAX

256Mb: x16 Mobile SDRAM

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MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

17. Required clocks are specified by JEDEC function-

ality and are not dependent on any timing param-
eter.

18. The I

current will increase or decrease propor-

tionally according to the amount of frequency al-
teration for the test condition.

19. Address transitions average one transition every

two clocks.

20. CLK must be toggled a minimum of two times dur-

ing this period.

21. Based on

CK = 8ns for -8,

CK = 10ns for -10.

22. V

overshoot: V

(MAX) = V

Q + 2V for a pulse

width

3ns, and the pulse width cannot be greater

than one third of the cycle rate. V

undershoot: V

(MIN) = -2V for a pulse width

1/3

CK.

23. The clock frequency must remain constant (stable

clock is defined as a signal cycling within timing
constraints specified for the clock pin) during ac-
cess or precharge states (READ, WRITE, including

WR, and PRECHARGE commands). CKE may be

used to reduce the data rate.

24. Auto precharge mode only. The precharge timing

budget (

RP) begins 7ns after the first clock delay,

after the last WRITE is executed.

25. Precharge mode only.
26. JEDEC and PC100 specify three clocks.
27.

AC for -8 at CL = 3 with no load is 5.4ns and is

guaranteed by design.

28. Parameter guaranteed by design.

Maximum capacitance can be 3.0 pF but not

desired.

Maximum capacitance can be 5.0pF but not

desired.

C. Maximum capacitance can be 3.3pF but not

desired.

D. Target values listed with alternative values in

parentheses.

RFC must be less than or equal to

RC+1CLK

XSR must be less than or equal to

RC+1CLK

For full I/V relationships see IBIS model.

29. PC100 specifies a maximum of 4pF.
30. PC100 specifies a maximum of 5pF.
31. PC100 specifies a maximum of 6.5pF.
32. For -8, CL = 2 and

CK = 10ns; for -10, CL = 3 and

CK = 10ns.

33. CKE is HIGH during refresh command period

RFC (MIN) else CKE is LOW. The I

6 limit is actu-

ally a nominal value and does not result in a fail
value.

34. Measured at nominal value at 70°C.

NOTES

All voltages referenced to V

This parameter is sampled; f = 1 MHz, T

= 25°C;

0.9V bias, 200mV swing, V

= +2.5V, V

Q = +2.5V.

is dependent on output loading and cycle rates.

Specified values are obtained with minimum cycle
time and the outputs open.

Enables on-chip refresh and address counters.

The minimum specifications are used only to
indicate cycle time at which proper operation over
the full temperature range (0°C

+70°C and -

40°C

+85°C for IT parts) is ensured.

An initial pause of 100µs is required after power-
up, followed by two AUTO REFRESH commands,
before proper device operation is ensured. (V

and V

Q must be powered up simultaneously. V

and V

Q must be at same potential.) The two

AUTO REFRESH command wake-ups should be
repeated any time the

REF refresh requirement is

exceeded.

AC characteristics assume

T = 1ns.

In addition to meeting the transition rate specifi-
cation, the clock and CKE must transit between V

and V

(or between V

and V

) in a monotonic

manner.

Outputs measured at 0.9V with equivalent load:

30pF

10.

HZ defines the time at which the output achieves

the open circuit condition; it is not a reference to
V

or V

. The last valid data element will meet

OH before going High-Z.

11. AC timing and I

tests have V

= 0.0V and V

1.65V,

with timing referenced to V

/2 crossover point. If

the input transition time is longer than 1 ns, then
the timing is referenced at V

(MAX) and V

(MIN)

and no longer at the V

/2 crossover point.

12. Other input signals are allowed to transition no

more than once every two clocks and are otherwise
at valid V

or V

levels.

13. I

specifications are tested after the device is prop-

erly initialized.

14. Timing actually specified by

CKS; clock(s) speci-

fied as a reference only at minimum cycle rate.

15. Timing actually specified by

WR plus

RP; clock(s)

specified as a reference only at minimum cycle rate.

16. Timing actually specified by

WR.

256Mb: x16 Mobile SDRAM

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MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

INITIALIZE AND LOAD MODE REGISTER

CKE

BA0, BA1

Load Extended

Mode Register

Load Mode

CKS

Power-up:
V

and

CLK stable

T = 100µs

CKH

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

DQML/U (x16)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

High-Z

A0-A9, A11, A12

A10

ALL BANKS

CLK

COMMAND

LMR4

NOP

PRE3

LMR4

AR4

ACT4

CMH

CMS

BA0 = L,
BA1 = H

tAS tAH

BA0 = L,

BA1 = L

(

)

(

)

(

)

(

)

CODE CODE

tAS tAH

CODE CODE

(

)

(

)

(

)

(

)

PRE

ALL BANKS

tAH

NOTE:

1. The two AUTO REFRESH commands at T9 and T19 may be applied before either LOAD MODE REGISTER (LMR) command.
2. PRE = PRECHARGE command, LMR = LOAD MODE REGISTER command, AR = AUTO REFRESH command, ACT = ACTIVE command, RA = Row Address,
BA = Bank Address
3. Optional refresh command.
4. The Load Mode Register for both MR/EMR and 2 Auto Refresh commands can be in any order. However, all must occur prior to an Active command.
5. Device timing is -10 with 100MHz clock.

(

)

(

)

(

)

(

)

T19

T29

(

)

(

)

(

)

(

)

DON'T CARE

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

MRD

RFC

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKH

CKS

2.5

CMH

CMS

2.5

MRD

RFC

100

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

POWER-DOWN MODE

tCH

tCL

tCK

Two clock cycles

CKE

CLK

All banks idle, enter
power-down mode

Precharge all

active banks

Input buffers gated off while in

power-down mode

Exit power-down mode

(

)

(

)

(

)

(

)

DON'T CARE

tCKS

COMMAND

tCMH

tCMS

PRECHARGE

NOP

ACTIVE

NOP

(

)

(

)

(

)

(

)

All banks idle

BA0, BA1

BANK

BANK(S)

(

)

(

)

(

)

(

)

High-Z

tAH

tAS

tCKH

tCKS

DQM/

DQML, DQMU

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

A0-A9, A11, A12

ROW

(

)

(

)

(

)

(

)

ALL BANKS

SINGLE BANK

A10

ROW

(

)

(

)

(

)

(

)

Tn + 1

Tn + 2

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

NOTE: 1. Violating refresh requirements during power-down may result in a loss of data.

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CK (1)

CKH

CKS

2.5

CMH

CMS

2.5

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

CLOCK SUSPEND MODE

tCH

tCL

tCK

tAC

tLZ

DQM/

DQML, DQMU

CLK

A0-A9, A11, A12

BA0, BA1

A10

tOH

OUT

tAH

tAS

tAH

tAS

tAH

tAS

BANK

tDH

OUT

tAC

tHZ

OUT

+ 1

COMMAND

tCMH

tCMS

NOP

READ

WRITE

DON'T CARE

UNDEFINED

CKE

tCKS tCKH

BANK

COLUMN m

tDS

OUT

+ 1

NOP

tCKH

tCKS

tCMH

tCMS

COLUMN e2

NOTE: 1. For this example, the burst length = 2, the CAS latency = 3, and auto precharge is disabled.

2. x16: A9, A11 and A12 = "Don't Care"

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKH

CKS

2.5

CMH

CMS

2.5

HZ (3)

HZ (2)

HZ (1)

2.5

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

AUTO REFRESH MODE

tCH

tCL

tCK

CKE

CLK

tRFC

RFC

(

)

(

)

(

)

(

)

(

)

(

)

tRP

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

COMMAND

tCMH

tCMS

NOP

(

)

(

)

(

)

(

)

BANK

ACTIVE

AUTO

REFRESH

(

)

(

)

(

)

(

)

NOP

PRECHARGE

Precharge all

active banks

AUTO

REFRESH

High-Z

BA0, BA1

BANK(S)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

tAH

tAS

tCKH

tCKS

(

)

(

)

NOP

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

DQM /

DQML, DQMU

A0-A9, A11, A12

ROW

(

)

(

)

(

)

(

)

ALL BANKS

SINGLE BANK

A10

ROW

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

DON'T CARE

Tn + 1

To + 1

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CK (1)

CKH

CKS

2.5

CMH

CMS

2.5

RFC

100

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

NOTE:

1. Each AUTO REFRESH command performs a refresh cycle. Back-to-back commands are not required.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

SELF REFRESH MODE

tCH

tCL

tCK

tRP

CKE

CLK

Enter self refresh mode

Precharge all

active banks

tXSR

CLK stable prior to exiting

self refresh mode

Exit self refresh mode

(Restart refresh time base)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

DON'T CARE

COMMAND

tCMH

tCMS

AUTO

REFRESH

PRECHARGE

NOP

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

BA0, BA1

BANK(S)

(

)

(

)

(

)

(

)

High-Z

tCKS

AUTO

REFRESH

> tRAS

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

tCKH

tCKS

DQM/

DQML, DQMH

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

tCKS

A0-A12

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

ALL BANKS

SINGLE BANK

A10

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

Tn + 1

To + 1

To + 2

(

)

(

)

(

)

(

)

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKH

CKS

2.5

CMH

CMS

2.5

RAS

120,000

XSR

100

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

NOTE:

1. No maximum time limit for Self Refresh mode.

RAS(MAX) applies to non-Self Refresh mode.

XSR requires minimum of two clocks regardless of frequency and timing.

3. As a general rule, any time Self Refresh is exited, the DRAM may not re-enter the Self Refresh Mode until all rows

have been refreshed via the Auto Refresh command at the distributed refresh rate,

REF, or faster. However, the

following exception is allowed. Self Refresh mode may be re-entered any time after exiting, provided all of the
following conditions are met:

a. The DRAM had been in the Self Refresh Mode for a minimum of 64ms prior to exiting.
b.

XSR is not violated.

c. At least two Auto Refresh commands are performed during each 7.81µs interval while the DRAM remains out of

Self Refresh mode.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

READ WITHOUT AUTO PRECHARGE

ALL BANKS

tCH

tCL

tCK

tAC

tLZ

tRP

tRAS

tRCD

CAS Latency

tRC

DQM/

DQML, DQMU

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tOH

OUT

tCMH

tCMS

tAH

tAS

tAH

tAS

tAH

tAS

ROW

BANK

ROW

BANK

tHZ

tOH

OUT

m + 3

tAC

tOH

tAC

tOH

tAC

OUT

m + 2

OUT

m + 1

COMMAND

tCMH

tCMS

PRECHARGE

NOP

ACTIVE

NOP

READ

NOP

ACTIVE

DISABLE AUTO PRECHARGE

SINGLE BANK

DON'T CARE

UNDEFINED

tCKH

tCKS

COLUMN m 2

NOTE: 1. For this example, the burst length = 4, the CAS latency = 2, and the READ burst is followed by a "manual"

PRECHARGE.

2. x16: A9, A11 and A12 = "Don't Care"

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

CMH

CMS

2.5

HZ (3)

HZ (2)

HZ (1)

2.5

RAS

120,000

100

RCD

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

READ WITH AUTO PRECHARGE

ENABLE AUTO PRECHARGE

tCH

tCL

tCK

tAC

tLZ

tRP

tRAS

tRCD

CAS Latency

tRC

DQM/

DQML, DQMU

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tOH

OUT

tCMH

tCMS

tAH

tAS

tAH

tAS

tAH

tAS

ROW

BANK

ROW

BANK

DON'T CARE

UNDEFINED

tHZ

tOH

OUT

m + 3

tAC

tOH

tAC

tOH

tAC

OUT

m + 2

OUT

m + 1

COMMAND

tCMH

tCMS

NOP

ACTIVE

NOP

READ

NOP

ACTIVE

NOP

tCKH

tCKS

COLUMN m 2

NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.

2. x16: A9, A11 and A12 = "Don't Care."

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMH

CMS

2.5

HZ (3)

HZ (2)

HZ (1)

2.5

RAS

120,000

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

ALL BANKS

tCH

tCL

tCK

tAC

tLZ

tRP

tRAS

tRCD

CAS Latency

tRC

tOH

OUT

tCMH

tCMS

tAH

tAS

tAH

tAS

tAH

tAS

ROW

BANK

BANK(S)

BANK

ROW

BANK

tHZ

tCMH

tCMS

NOP

PRECHARGE

ACTIVE

NOP

READ

ACTIVE

NOP

DISABLE AUTO PRECHARGE

SINGLE BANKS

DON'T CARE

UNDEFINED

COLUMN m

tCKH

tCKS

DQM /

DQML, DQMU

CKE

CLK

A0-A9, A11,A12

BA0, BA1

A10

COMMAND

SINGLE READ WITHOUT AUTO PRECHARGE

NOTE: 1. For this example, the burst length = 1, the CAS latency = 2, and the READ burst is followed by a "manual"

PRECHARGE.

2. PRECHARGE command not allowed else

RAS would be violated.

3. x16: A9, A11 and A12 = "Don't Care"

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMH

CMS

2.5

HZ (3)

HZ (2)

HZ (1)

2.5

RAS

120,000

100

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

SINGLE READ WITH AUTO PRECHARGE

ENABLE AUTO PRECHARGE

tCH

tCL

tCK

tRP

tRAS

tRCD

CAS Latency

tRC

DQM /

DQML, DQMU

CKE

CLK

A0-A9, A11

BA0, BA1

A10

tCMH

tCMS

tAH

tAS

tAH

tAS

tAH

tAS

ROW

BANK

ROW

BANK

DON'T CARE

UNDEFINED

tHZ

t OH

OUT

tAC

COMMAND

tCMH

tCMS

NOP2

READ

ACTIVE

NOP

NOP2

ACTIVE

NOP

tCKH

tCKS

COLUMN m3

NOP

NOTE: 1. For this example, the burst length = 1, and the CAS latency = 2.

2. READ command not allowed else

RAS would be violated since AUTO PRECHARGE is enabled.

3. x16: A9, A11 and A12 = "Don't Care"

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMH

CMS

2.5

HZ (3)

HZ (2)

HZ (1)

2.5

RAS

120,000

100

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

ALTERNATING BANK READ ACCESSES

ENABLE AUTO PRECHARGE

tCH

tCL

tCK

tAC

tLZ

DQM/

DQML, DQMU

CLK

A0-A9, A11, A12

BA0, BA1

A10

tOH

OUT

tCMH

tCMS

tAH

tAS

tAH

tAS

tAH

tAS

ROW

DON'T CARE

UNDEFINED

tOH

OUT

m + 3

tAC

tOH

tAC

tOH

tAC

OUT

m + 2

OUT

m + 1

COMMAND

tCMH

tCMS

NOP

ACTIVE

NOP

READ

NOP

ACTIVE

tOH

OUT

tAC

READ

ENABLE AUTO PRECHARGE

ROW

ACTIVE

ROW

BANK 0

BANK 3

BANK 0

CKE

tCKH

tCKS

COLUMN m 2

COLUMN b 2

tRP - BANK 0

tRAS - BANK 0

tRCD - BANK 0

CAS Latency - BANK 0

tRCD - BANK 1

CAS Latency - BANK 1

RC - BANK 0

RRD

NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.

2. x16: A9, A11 and A12 = "Don't Care"

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKS

2.5

CMH

CMS

2.5

RAS

120,000

100

RCD

RRD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

CKH

*CAS latency indicated in parentheses.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

READ FULL-PAGE BURST

tCH

tCL

tCK

tAC

tLZ

tRCD

CAS Latency

DQM/

DQML, DQMH

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tOH

OUT

tCMH

tCMS

tAH

tAS

tAH

tAS

tAC

tOH

OUT

m+1

ROW

tHZ

tAC

tOH

OUT

m+1

tAC

tOH

OUT

m+2

tAC

tOH

OUT

m-1

tAC

tOH

Dout m

Full-page burst does not self-terminate.

Can use BURST TERMINATE command.

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

Full page completed

512 (x16) locations within same row
1,024 (x8) locations within same row
2,048 (x4) locations within same row

DON'T CARE

UNDEFINED

COMMAND

tCMH

tCMS

NOP

ACTIVE

NOP

READ

NOP

BURST TERM

NOP

(

)

(

)

(

)

(

)

NOP

(

)

(

)

(

)

(

)

tAH

tAS

BANK

(

)

(

)

(

)

(

)

BANK

tCKH

tCKS

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

COLUMN m 2

Tn + 1

Tn + 2

Tn + 3

Tn + 4

NOTE: 1. For this example, the CAS latency = 2.

2. x16: A9, A11 and A12 = "Don't Care"
3. Page left open; no

RP.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKH

CKS

2.5

CMH

CMS

2.5

HZ (3)

HZ (2)

HZ (1)

2.5

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

*CAS latency indicated in parentheses.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

READ DQM OPERATION

tCH

tCL

tCK

tRCD

CAS Latency

DQM/

DQML, DQMU

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tCMS

ROW

BANK

ROW

BANK

DON'T CARE

UNDEFINED

tAC

OUT

tOH

OUT

m + 3

OUT

m + 2

tHZ

tCMH

COMMAND

NOP

ACTIVE

NOP

READ

NOP

tHZ

tAC

tOH

tAC

tOH

tAH

tAS

tCMS tCMH

tAH

tAS

tAH

tAS

tCKH

tCKS

ENABLE AUTO PRECHARGE

DISABLE AUTO PRECHARGE

COLUMN m 2

NOTE:

1. For this example, the burst length = 4, and the CAS latency = 2.
2. x16: A9, A11 and A12 = "Don't Care"

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKH

CKS

2.5

CMH

CMS

2.5

HZ (3)

HZ (2)

HZ (1)

2.5

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

AC (3)

AC (2)

AC (1)

2.5

CK (3)

CK (2)

CK (1)

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

WRITE WITHOUT AUTO PRECHARGE

DISABLE AUTO PRECHARGE

tCH

tCL

tCK

tRP

tRAS

tRCD

tRC

DQM/

DQML, DQMU

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tCMH

tCMS

tAH

tAS

ROW

BANK

ROW

BANK

DON'T CARE

tDH

tDS

m + 1

m + 2

m + 3

COMMAND

tCMH

tCMS

NOP

ACTIVE

NOP

WRITE

PRECHARGE

tAH

tAS

tAH

tAS

tDH

tDS

tDH

tDS

tDH

tDS

SINGLE BANK

tCKH

tCKS

COLUMN m2

ROW

BANK

ROW

ACTIVE

NOP

ALL BANKs

NOTE: 1. For this example, the burst length = 4, and the WRITE burst is followed by a "manual" PRECHARGE.

2. x16: A9, A11 and A12 = "Don't Care"
3. 14ns to 15ns is required between <D

m> and the PRECHARGE command, regardless of frequency.

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMH

CMS

2.5

RAS

120,000

100

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

WRITE WITH AUTO PRECHARGE

ENABLE AUTO PRECHARGE

tCH

tCL

tCK

tRP

tRAS

tRCD

tRC

DQM/

DQML, DQMU

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tCMH

tCMS

tAH

tAS

ROW

BANK

ROW

BANK

tWR

DON'T CARE

tDH

tDS

m + 1

m + 2

m + 3

COMMAND

tCMH

tCMS

NOP

ACTIVE

NOP

WRITE

NOP

ACTIVE

tAH

tAS

tAH

tAS

tDH

tDS

tDH

tDS

tDH

tDS

tCKH

tCKS

NOP

COLUMN

NOTE: 1. For this example, the burst length = 4.

2. x16: A9, A11 and A12 = "Don't Care"

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMS

2.5

RAS

120,000

100

RCD

1 CLK +

7ns

5ns

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

CMH

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

SINGLE WRITE WITHOUT AUTO PRECHARGE

DISABLE AUTO PRECHARGE

ALL BANKS

tCH

tCL

tCK

tRP

tRAS

tRCD

tRC

DQM /

DQML, DQMU

CKE

CLK

A0-A9, A11

BA0, BA1

A10

tCMH

tCMS

tAH

tAS

ROW

BANK BANK

BANK

ROW

BANK

t WR

tDH

tDS

COMMAND

tCMH

tCMS

NOP

PRECHARGE

ACTIVE

NOP

WRITE

ACTIVE

NOP

tAH

tAS

tAH

tAS

SINGLE BANK

tCKH

tCKS

COLUMN m 3

DON'T CARE

NOTE: 1. For this example, the burst length = 1, and the WRITE burst is followed by a "manual" PRECHARGE.

2. PRECHARGE command not allowed else

RAS would be violated.

3. x16: A9, A11 and A12 = "Don't Care"
4. 14ns to 15ns is required between <D

m> and the PRECHARGE command, regardless of frequency. With a single write

WR has been increased to meet minimum

RAS requirement.

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMH

CMS

2.5

RAS

120,000

100

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

SINGLE WRITE WITH AUTO PRECHARGE

ENABLE AUTO PRECHARGE

tCH

tCL

tCK

tRP

tRAS

tRCD

tRC

DQM/

DQML, DQMU

CKE

A0-A9, A11, A12

BA0, BA1

A10

tCMH

tCMS

tAH

tAS

ROW

BANK

ROW

BANK

tWR

COMMAND

tCMH

tCMS

NOP2

NOP

ACTIVE

NOP2

WRITE

NOP

ACTIVE

tAH

tAS

tAH

tAS

tDH

tDS

tCKH

tCKS

NOP

COLUMN m 3

DON'T CARE

NOTE: 1. For this example, the burst length = 1.

2. WRITE command not allowed else

RAS would be violated.

3. x16: A9, A11 and A12 = "Don't Care"
4. Requires one clock plus time (5ns to 7ns) with auto precharge or 14ns to 15ns with PRECHARGE.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMS

2.5

RAS

120,000

100

RCD

1 CLK +

7ns

5ns

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

CMH

*CAS latency indicated in parentheses.

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

ALTERNATING BANK WRITE ACCESSES

tCH

tCL

tCK

CLK

DON'T CARE

tDH

tDS

m + 1

m + 2

m + 3

COMMAND

tCMH

tCMS

NOP

ACTIVE

NOP

WRITE

NOP

ACTIVE

tDH

tDS

tDH

tDS

tDH

tDS

ACTIVE

WRITE

tDH

tDS

b + 1

b + 3

tDH

tDS

tDH

tDS

ENABLE AUTO PRECHARGE

DQM/

DQML, DQMU

A0-A9, A11, A12

BA0, BA1

A10

tCMH

tCMS

tAH

tAS

tAH

tAS

tAH

tAS

ROW

ENABLE AUTO PRECHARGE

ROW

BANK 0

BANK 1

BANK 0

BANK 1

CKE

tCKH

tCKS

b + 2

tDH

tDS

COLUMN b 3

COLUMN m3

tRP - BANK 0

tRAS - BANK 0

tRCD - BANK 0

RCD - BANK 0

tWR - BANK 0

WR - BANK 1

tRCD - BANK 1

RC - BANK 0

RRD

NOTE: 1. For this example, the burst length = 4.

2. Requires one clock plus time (5ns or 7ns) with auto precharge or 14ns to 15ns with PRECHARGE.
3. x16: A9, A11 and A12 = "Don't Care"

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CMS

2.5

RAS

120,000

100

RCD

RRD

1 CLK +

7ns

5ns

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

CKH

CKS

2.5

CMH

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

WRITE FULL-PAGE BURST

tCH

tCL

tCK

tRCD

DQM/

DQML, DQMH

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tCMS

tAH

tAS

tAH

tAS

ROW

Full-page burst does
not self-terminate.
Can use BURST TERMINATE
command to stop.

2, 3

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

Full page completed

DON'T CARE

COMMAND

tCMH

tCMS

NOP

ACTIVE

NOP

WRITE

BURST TERM

NOP

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

tDH

tDS

m + 1

m + 2

m + 3

tDH

tDS

tDH

tDS

tDH

tDS

m - 1

tDH

tDS

tAH

tAS

BANK

(

)

(

)

(

)

(

)

BANK

tCMH

tCKH

tCKS

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

512 (x16) locations within same row

1,024 (x8) locations within same row
2,048 (x4) locations within same row

COLUMN

Tn + 1

Tn + 2

Tn + 3

NOTE: 1. x16: A9, A11 and A12 = "Don't Care"

WR must be satisfied prior to PRECHARGE command.

3. Page left open; no

RP.

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKH

CKS

2.5

CMH

CMS

2.5

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

WRITE DQM OPERATION

tCH

tCL

tCK

tRCD

DQM/

DQML, DQMU

CKE

CLK

A0-A9, A11, A12

BA0, BA1

A10

tCMS

tAH

tAS

ROW

BANK

ROW

BANK

ENABLE AUTO PRECHARGE

m + 3

tDH

tDS

m + 2

tCMH

COMMAND

NOP

ACTIVE

NOP

WRITE

NOP

DON'T CARE

tCMS tCMH

tDH

tDS

tDH

tDS

tAH

tAS

tAH

tAS

DISABLE AUTO PRECHARGE

tCKH

tCKS

COLUMN m2

NOTE: 1. For this example, the burst length = 4.

2. x16: A9, A11 and A12 = "Don't Care"

*CAS latency indicated in parentheses.

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

CKH

CKS

2.5

CMH

CMS

2.5

RCD

TIMING PARAMETERS

-8

-10

SYMBOL*

MIN

MAX

MIN

MAX

UNITS

2.5

CK (3)

CK (2)

CK (1)

256Mb: x16 Mobile SDRAM

Micron Technology, Inc., reserves the right to change products or specifications without notice.

MobileRamY26L_B.p65 Pub. 04/03

256Mb: x16

MOBILE SDRAM

PRELIMINARY

(Bottom View)

VFBGA "FG" PACKAGE

54-pin, 8mm x 14mm

BALL A1 ID

1.00 MAX

MOLD COMPOUND: EPOXY NOVOLAC

SUBSTRATE: PLASTIC LAMINATE

SOLDER BALL MATERIAL: EUTECTIC 63% Sn, 37% Pb or
62% Sn, 36% Pb, 2%Ag
SOLDER BALL PAD: Ø .27mm

14.00 ±0.10

BALL A1

BALL A9

BALL A1 ID

0.80 TYP

1.80 ±0.05
CTR

7.00 ±0.05

8.00 ±0.10

4.00 ±0.05

3.20 ±0.05

0.700 ±0.075

0.155 ±0.013

SEATING PLANE

6.40

0.10 C

54X

0.35

SOLDER BALL DIAMETER
REFERS TO POST REFLOW
CONDITION. THE PRE-
REFLOW DIAMETER IS Ø 0.33

NOTE: 1. All dimensions are in millimeters.

8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900

E-mail: prodmktg@micron.com, Internet: http://www.micron.com, Customer Comment Line: 800-932-4992

Micron, the M logo, and the Micron logo are trademarks and/or service marks of Micron Technology, Inc.

All other trademarks are the property of their respective owners.

Data Sheet Designation

Preliminary: This data sheet contains initial charac-

terization limits that are subject to change upon full
characterization of production devices.

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Document Outline

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