PMC PM3351 Datasheet

PMC-Sierra,Inc.

Preliminary

Single-Port 10/100 Mbit/s Ethernet Switch

PM3351

ELAN 1x100

FEATURES

• Single-chip, 1-port, full-duplex or half­duplex, 10/100BaseT switching dev ice
for low-cost unmanag ed and manag ed
networks.

• On-chip SmartPath 50 MHz RISC
CPU core, multi-channel DMA
controller, MAC-layer interface logic,
FIFOs, PCI-based expans ion port, and
a flexible memory controller.

• CPU supports backgro und 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 th e PM3350
8-port 10 Mbit/s switc h dev ic e; m ay 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, ad dress
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 in­band.

• Store-and-forward operation with full
error checki ng and filtering.

• Flow contr ol supported for both full­duplex 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 operati on 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

PCI Expansion

Bus

PCI Bus

Interface

Expansion

Registers

50 MHz
Embedded
RISC CPU

I

CacheD Cache

Transmit

Channel Logic

Receive DMA

Controller

External

Memory

Interface

Transmit

FIFO

Receive

FIFO

100BaseT

Transmit MAC

100BaseT

Receive MAC

100BaseT

MII Interface

PMC-970278 (P4)

SRAM/EPROM





1998 PMC-Sierra, Inc. October, 1998

Preliminary

PM3351 ELAN 1x100

Single-Port 10/100 Mbit/s Ethernet Switch

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.

8×10BaseT

Quad

PHY

PM3350

(/$1[

EEPROM

Quad

PHY

PM3350

(/$1[

Quad

Quad

PHY

PHY

8×10BaseT

8×10BaseT

Quad

PHY

PM3350

(/$1[

EDO

DRAM

PCI Backplane

EDO

DRAM

Quad

PHY

PM3350

(/$1[

Quad

PHY

8×10BaseT

Quad

PHY

EDO

(/$1[

DRAM

10/100BaseT

10/100 PHY

PM3351

EDO

DRAM

SRAM

PM3351

(/$1[

10/100 PHY

10/100BaseT

SRAM

Head Office:
PMC-Sierra, Inc.
#105 - 8555 Baxter Place
Burnaby, B.C. V5A 4V7
Canada
Tel: [phone]
Fax: [phone]

To order documentation,
send email to:
[e-mail]
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 info rmation,
send email to:
[e-mail]

PMC-970278 (P4)
 1998 PMC-Sierra, Inc.
October, 1998
SmartPath is a trademark
of PMC-Sierra, Inc.