Features

Single Supply for Read and Write: 2.7 to 3.6V (BV), 3.0 to 3.6V (LV)

Fast Read Access Time 70 ns

Internal Program Control and Timer

Sector Architecture

One 16K Bytes Boot Block with Programming Lockout
Two 8K Bytes Parameter Blocks
Two Main Memory Blocks (96K, 128K Bytes)

Fast Erase Cycle Time 10 Seconds

Byte-by-Byte Programming 30 µs/Byte Typical

Hardware Data Protection

DATA Polling for End of Program Detection

Low Power Dissipation

25 mA Active Current
50 µA CMOS Standby Current

Typical 10,000 Write Cycles

Description

The AT49BV/LV002(N)(T) is a 3-volt-only in-system reprogrammable Flash Memory.
Its 2 megabits of memory is organized as 262,144 words by 8 bits. Manufactured with
Atmel's advanced nonvolatile CMOS technology, the device offers access times to
70 ns with power dissipation of just 90 mW over the commercial temperature range.

2-megabit
(256K x 8)
Single 2.7-volt

Battery-Voltage

Flash Memory

AT49BV002
AT49LV002
AT49BV002N
AT49LV002N
AT49BV002T
AT49LV002T
AT49BV002NT
AT49LV002NT

Rev. 0982DFLASH02/03

PLCC Top View

Pin Configurations

Pin Name

Function

A0 - A17

Addresses

Chip Enable

Output Enable

Write Enable

RESET

I/O0 - I/O7

Data Inputs/Outputs

Don't Connect

I/O0

A14

A13

A11

A10

I/O7

I/O1

I/O2

GND

I/O3

I/O4

I/O5

I/O6

A12

A15

A16

RESET*

VCC

A17

DIP Top View

VSOP Top View (8 x 14 mm) or

TSOP Top View (8 x 20 mm)

Type 1

*RESET

A16

A15

A12

I/O0

I/O1

I/O2

GND

VCC

A17

A14

A13

A11

A10

I/O7

I/O6

I/O5

I/O4

I/O3

A11

A13

A14

A17

VCC

*RESET

A16

A15

A12

A10

I/O7

I/O6

I/O5

I/O4

I/O3

GND

I/O2

I/O1

I/O0

Note:

*This pin is a DC on the AT49BV002N(T) and AT49LV002N(T).

AT49BV/LV002(N)(T)

0982DFLASH02/03

When the device is deselected, the CMOS standby current is less than 50 µA. For the
AT49BV/LV002N(T) pin 1 for the DIP and PLCC packages and pin 9 for the TSOP package
a r e d o n ' t c o n n e c t p i n s . T o a l l o w f o r s i m p l e i n - s y s t e m r e p r o g r a m m a b i l i t y , t h e
AT49BV/LV002(N)(T) does not require high input voltages for programming. Five-volt-only
commands determine the read and programming operation of the device. Reading data out of
the device is similar to reading from an EPROM; it has standard CE, OE, and WE inputs to
avoid bus contention. Reprogramming the AT49BV/LV002(N)(T) is performed by erasing a
block of data and then programming on a byte by byte basis. The byte programming time is a
fast 50

µs. The end of a program cycle can be optionally detected by the DATA polling feature.

Once the end of a byte program cycle has been detected, a new access for a read or program
can begin. The typical number of program and erase cycles is in excess of 10,000 cycles.

The device is erased by executing the erase command sequence; the device internally con-
trols the erase operations. There are two 8K byte parameter block sections and two main
memory blocks.

The device has the capability to protect the data in the boot block; this feature is enabled by a
command sequence. The 16K-byte boot block section includes a reprogramming lock out fea-
ture to provide data integrity. The boot sector is designed to contain user secure code, and
when the feature is enabled, the boot sector is protected from being reprogrammed.

In the AT49BV/LV002N(T), once the boot block programming lockout feature is enabled, the
contents of the boot block are permanent and cannot be changed. In the AT49BV/LV002(T),
once the boot block programming lockout feature is enabled, the contents of the boot block
cannot be changed with input voltage levels of 5.5 volts or less.

Block Diagram

CONTROL

LOGIC

Y DECODER

PARAMETER

BLOCK 1

(8K BYTES)

BOOT BLOCK

(16K BYTES)

RESET

ADDRESS

INPUTS

VCC

GND

AT49BV/LV002(N)

DATA INPUTS/OUTPUTS

I/O7 - I/O0

X DECODER

PARAMETER

BLOCK 2

(8K BYTES)

MAIN MEMORY

BLOCK 1

(96K BYTES)

MAIN MEMORY

BLOCK 2

(128K BYTES)

PROGRAM

DATA LATCHES

Y-GATING

INPUT/OUTPUT

BUFFERS

3FFFF

20000

1FFFF

08000

07FFF

06000

05FFF

04000

03FFF

00000

PARAMETER

BLOCK 1

(8K BYTES)

BOOT BLOCK

(16K BYTES)

AT49BV/LV002(N)T

DATA INPUTS/OUTPUTS

I/O7 - I/O0

PARAMETER

BLOCK 2

(8K BYTES)

MAIN MEMORY

BLOCK 1

(96K BYTES)

MAIN MEMORY

BLOCK 2

(128K BYTES)

PROGRAM

DATA LATCHES

Y-GATING

INPUT/OUTPUT

BUFFERS

3FFFF

3C000

3BFFF

3A000

39FFF

38000

37FFF

20000

1FFFF

00000

AT49BV/LV002(N)(T)

0982DFLASH02/03

Device
Operation

READ: The AT49BV/LV002(N)(T) is accessed like an EPROM. When CE and OE are low and
WE is high, the data stored at the memory location determined by the address pins is asserted
on the outputs. The outputs are put in the high impedance state whenever CE or OE is high.
This dual-line control gives designers flexibility in preventing bus contention.

COMMAND SEQUENCES: When the device is first powered on it will be reset to the read or
standby mode depending upon the state of the control line inputs. In order to perform other
device functions, a series of command sequences are entered into the device. The command
sequences are shown in the Command Definitions table. The command sequences are written
by applying a low pulse on the WE or CE input with CE or WE low (respectively) and OE high.
The address is latched on the falling edge of CE or WE, whichever occurs last. The data is
latched by the first rising edge of CE or WE. Standard microprocessor write timings are used.
The address locations used in the command sequences are not affected by entering the com-
mand sequences.

RESET: A RESET input pin is provided to ease some system applications. When RESET is at
a logic high level, the device is in its standard operating mode. A low level on the RESET input
halts the present device operation and puts the outputs of the device in a high impedance
state. If the RESET pin makes a high to low transition during a program or erase operation, the
operation may not be successfully completed and the operation will have to be repeated after
a high level is applied to the RESET pin. When a high level is reasserted on the RESET pin,
the device returns to the read or standby mode, depending upon the state of the control inputs.
By applying a 12V

± 0.5V input signal to the RESET pin, the boot block array can be repro-

grammed even if the boot block lockout feature has been enabled (see Boot Block
Programming Lockout Override section). The RESET feature is not available on the
AT49BV/LV002N(T).

ERASURE: Before a byte can be reprogrammed, the main memory block or parameter block
which contains the byte must be erased. The erased state of the memory bits is a logical "1".
The entire device can be erased at one time by using a 6-byte software code. The software
chip erase code consists of 6-byte load commands to specific address locations with a specific
data pattern (please refer to the Chip Erase Cycle Waveforms).

After the software chip erase has been initiated, the device will internally time the erase opera-
tion so that no external clocks are required. The maximum time needed to erase the whole
chip is t

. If the boot block lockout feature has been enabled, the data in the boot sector will

not be erased.

CHIP ERASE: If the boot block lockout has been enabled, the Chip Erase function will erase
Parameter Block 1, Parameter Block 2, Main Memory Block 1, and Main Memory Block 2 but
not the boot block. If the Boot Block Lockout has not been enabled, the Chip Erase function
will erase the entire chip. After the full chip erase the device will return back to read mode. Any
command during chip erase will be ignored.

SECTOR ERASE: As an alternative to a full chip erase, the device is organized into sectors
that can be individually erased. There are two 8K-byte parameter block sections and two main
memory blocks. The 8K-byte parameter block sections can be independently erased and
reprogrammed. The two main memory sections are designed to be used as alternative mem-
ory sectors. That is, whenever one of the blocks has been erased and reprogrammed, the
other block should be erased and reprogrammed before the first block is again erased. The
Sector Erase command is a six bus cycle operation. The sector address is latched on the fall-
ing WE edge of the sixth cycle while the 30H data input command is latched at the rising edge
of WE. The sector erase starts after the rising edge of WE of the sixth cycle. The erase opera-
tion is internally controlled; it will automatically time to completion.

AT49BV/LV002(N)(T)

0982DFLASH02/03

BYTE PROGRAMMING: Once the memory array is erased, the device is programmed (to a
logical "0") on a byte-by-byte basis. Please note that a data "0" cannot be programmed back to
a "1"; only erase operations can convert "0"s to "1"s. Programming is accomplished via the
internal device command register and is a 4 bus cycle operation (please refer to the Command
Definitions table). The device will automatically generate the required internal program pulses.

The program cycle has addresses latched on the falling edge of WE or CE, whichever occurs
last, and the data latched on the rising edge of WE or CE, whichever occurs first. Program-
ming is completed after the specified t

cycle time. The DATA polling feature may also be

used to indicate the end of a program cycle.

BOOT BLOCK PROGRAMMING LOCKOUT: The device has one designated block that has
a programming lockout feature. This feature prevents programming of data in the designated
block once the feature has been enabled. The size of the block is 16K bytes. This block,
referred to as the boot block, can contain secure code that is used to bring up the system.
Enabling the lockout feature will allow the boot code to stay in the device while data in the rest
of the device is updated. This feature does not have to be activated; the boot block's usage as
a write protected region is optional to the user. The address range of the boot block is 00000
to 03FFF for the AT49BV/LV002(N) while the address range of the boot block is 3C000 to
3FFFF for the AT49BV/LV002(N)T.

Once the feature is enabled, the data in the boot block can no longer be erased or pro-
grammed with input voltage of 5.5V or less. Data in the main memory block can still be
changed through the regular programming method. To activate the lockout feature, a series of
six program commands to specific addresses with specific data must be performed. Please
refer to the Command Definitions table.

BOOT BLOCK LOCKOUT DETECTION: A software method is available to determine if pro-
gramming of the boot block section is locked out. When the device is in the software product
identification mode (see Software Product Identification Entry and Exit sections) a read from
address location 00002H will show if programming the boot block is locked out for the
AT49BV/LV002(N), and a read from address location 3C002H will show if programming the
bootblock is locked out for AT49BV/LV002(N)T. If the data on I/O0 is low, the boot block can
be programmed; if the data on I/O0 is high, the program lockout feature has been activated
and the block cannot be programmed. The software product identification code should be
used to return to standard operation.

BOOT BLOCK PROGRAMMING LOCKOUT OVERRIDE: The user can override the boot
block programming lockout by taking the RESET pin to 12 volts during the entire chip erase,
sector erase or byte programming operation. When the RESET pin is brought back to TTL lev-
els the boot block programming lockout feature is again active. This feature is not available on
the AT49BV/LV002N(T).

PRODUCT IDENTIFICATION: The product identification mode identifies the device and man-
ufacturer as Atmel. It may be accessed by hardware or software operation. The hardware
operation mode can be used by an external programmer to identify the correct programming
algorithm for the Atmel product.

For details, see Operating Modes (for hardware operation) or Software Product Identification.
The manufacturer and device code is the same for both modes.

AT49BV/LV002(N)(T)

0982DFLASH02/03

DATA POLLING: The AT49BV/LV002(N)(T) features DATA polling to indicate the end of a
program cycle. During a program cycle an attempted read of the last byte loaded will result in
the complement of the loaded data on I/O7. Once the program cycle has been completed, true
data is valid on all outputs and the next cycle may begin. DATA polling may begin at any time
during the program cycle.

TOGGLE BIT: In addition to DATA polling the AT49BV/LV002(N)(T) provides another method
for determining the end of a program or erase cycle. During a program or erase operation,
successive attempts to read data from the device will result in I/O6 toggling between one and
zero. Once the program cycle has completed, I/O6 will stop toggling and valid data will be
read. Examining the toggle bit may begin at any time during a program cycle.

HARDWARE DATA PROTECTION: Hardware features protect against inadvertent programs
to the AT49BV/LV002(N)(T) in the following ways: (a) V

sense: if V

is below 1.8V (typical),

the program function is inhibited. (b) Program inhibit: holding any one of OE low, CE high or
WE high inhibits program cycles. (c) Noise filter: pulses of less than 15 ns (typical) on the WE
or CE inputs will not initiate a program cycle.

Document Outline

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Document Outline

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: AT49LV002T-12