PMC-970278 (P4)
1998 PMC-Sierra, Inc. October, 1998
PM3351
Preliminary
PMC-Sierra,Inc.
Single-Port 10/100 Mbit/s Ethernet Switch
ELAN 1x100
FEATURES
Single-chip, 1-port, full-duplex or half-
duplex, 10/100BaseT switching device
for low-cost unmanaged and managed
networks.
On-chip SmartPath
TM
50 MHz RISC
CPU core, multi-channel DMA
controller, MAC-layer interface logic,
FIFOs, PCI-based expansion port, and
a flexible memory controller.
CPU supports background applications
running on local OS (e.g., SNMP), and
real-time data-oriented applications
(e.g., packet forwarding and filtering
decisions).
Performs packet switching at a rate of
200 Mbit/s (full-duplex) or 100 Mbit/s
(half-duplex).
Fully compatible with the PM3350
8-port 10 Mbit/s switch device; may be
used to create a compact and
inexpensive mixed 10/100 Mbit/s
switching hub.
Filtering and switching at wire rates (up
to 148,8000 packets per second),
supporting a mix of Ethernet and
IEEE 802.3 protocols.
Expansion port supports a peak
system bandwidth of 1 Gbit/s, and is
compatible with industry-standard PCI
bus (version 2.1).
Performs all address learning, address
table management, and aging
functions for up to 32,768 MAC
addresses (limited by external
memory). Address learning rate of up
to 10,000 addresses per second.
Maximum broadcast/multicast at wire
rates with configurable broadcast
storm rate limiting.
Low-latency operation in both unicast
and broadcast modes.
Configuration, management, MIB
statistics, and diagnostics available in-
band.
Store-and-forward operation with full
error checking and filtering.
Flow control supported for both full-
duplex and half-duplex operation;
supports IEEE 802.3x PAUSE frame
flow control in full-duplex mode, and
supports user-enabled backpressure
flow control in half-duplex mode.
Maintains and collects per-port and
per-host statistics at wire rates.
Interfaces directly to industry-standard
100 Mbit/s transceivers with no glue
logic via the built-in Medium
Independent Interface (MII) port with
full support for the autonegotiation
function implemented by the PHY
devices.
Fully static CMOS operation at 50 MHz
clock rates.
Implemented with a 3.3 V core and a
5 V-compatible I/O.
Available in a 208-pin PQFP package.
BLOCK DIAGRAM
50 MHz
Embedded
RISC CPU
I
Cache
D
Cache
Transmit
Channel Logic
External
Memory
Interface
SRAM/EPROM
PCI Expansion
Bus
PCI Bus
Interface
Expansion
Registers
Transmit
FIFO
Receive DMA
Controller
100BaseT
Transmit MAC
Receive
FIFO
100BaseT
Receive MAC
100BaseT
MII Interface
Head Office:
PMC-Sierra, Inc.
#105 - 8555 Baxter Place
Burnaby, B.C. V5A 4V7
Canada
Tel: 604.415.6000
Fax: 604.415.6200
Preliminary
PM3351 ELAN 1x100
Single-Port 10/100 Mbit/s Ethernet Switch
To order documentation,
send email to:
document@pmc-sierra.com
or contact the head office,
Attn: Document Coordinator
All product documentation is available
on our web site at:
http://www.pmc-sierra.com
For corporate information,
send email to:
info@pmc-sierra.com
PMC-970278 (P4)
1998 PMC-Sierra, Inc.
October, 1998
SmartPath is a trademark
of PMC-Sierra, Inc.
TYPICAL APPLICATION
LOW-COST 10/100 Mbit/s ETHERNET SWITCH
The ELAN 1
100 chip is used to build low-cost 10/100 Mbit/s switches for server/backbone applications. A switch can be created
from the following:
PM3351s (one for every 100 Mbit/s port required),
one to seven PM3350s (one for every eight 10 Mbit/s ports required),
a bank of memory per device (60 ns EDO DRAM for each PM3350,
15 ns SRAM for each PM3351) for holding frame buffers and switching tables,
a single 256k
8-bit EPROM or EEPROM (initialization, configuration, and SNMP support firmware),
quad 10BaseT interface adapters (LXT944) for the PM3350s,
one 100 Mbit/s PHY device per PM3351, and
appropriate passive components.
A block diagram of a typical 32-port 10BaseT stackable switch with two 10/100 Mbit/s ports is shown. The PCI expansion bus is
used to seamlessly connect the ELAN 8
10s and ELAN 1
100s.
ED
O
DR
AM
PCI Backplane
Quad
PHY
Quad
PHY
8
10BaseT
PM3351
@G6I [
SRA
M
10/100 PHY
10/100BaseT
ED
O
DRA
M
Quad
PHY
Quad
PHY
8
10BaseT
ED
O
DR
A
M
Quad
PHY
Quad
PHY
8
10BaseT
SRA
M
10/100 PHY
10/100BaseT
PM3350
@G6I'
ED
O
DR
A
M
Quad
PHY
Quad
PHY
8
10BaseT
EE
PRO
M
PM3351
@G6I [
PM3350
@G6I'
PM3350
@G6I'
PM3350
@G6I'
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