P R E L I M I N A R Y
I N F O R M A T I O N
Distinctive Characteristics
SC220 – XpressFlow Engine
t Highly integrated central switch controller
XpressFlow 2020 Ethernet Routing Switch Chipset
t State of the art 0.35 micron 3.3 Volt CMOS
process
t 256-PIN PQFP package
t Operating frequency
C A M
(Optional)
à
à
à
-40
-50
-66
40 MHz maximum
50 MHz maximum
66 MHz maximum
ADDRESS
MAPPING
TABLE
SC220
16
t 16-bit external CAM interface
Supports ½k to 16k MAC addresses
t 32-bit Control Buffer Memory interface
à
XpressFlow
CONTROL
BUFFER
ENGINE
à
à
Supports 128k to 1M bytes
32
MEMORY
Utilize high performance 32-bit Syn-
chronous Burst SRAM
t Hardware assisted Buffer and Queue Man-
32
32
agement to minimize CPU overhead
XpressFlow BUS
XpressFlow BUS
t 32-bit Management Bus I/O interface
à
Allows host to access CAM and Control
Buffer Memory
à
à
Supports Big and Little Endian CPUs
Direct interface with various different
standard microprocessors including
386, 486 families and Motorola MPC se-
ries embedded processors
SC220 - XpressFlow Engine
t 32-bit XpressFlow Bus Interface
Switching bandwidth
à
General Description
- 1.28 Gbps @ 40 MHz system clock
- 1.60 Gbps @ 50 MHz system clock
- 2.10 Gbps @ 66.67 MHz system clock
The XpressFlow Engine contains the switching data base in-
terface and buffer management logic in order to do the switching
decision making for unicast, multicast, and broadcast frames.
Hardware assisted queue manager is incorporated to facilitate
buffer management. It also provides a generic Management Bus
interface to allow external processor to do initialization, learning,
VLAN, and RMON support, etc. In addition, a XpressFlow Bus
interface block is responsible for communicating with the Network
Access Controllers through the XpressFlow message passing
protocol.
à
Supports up to 8 Multi-port Network Ac-
cess Controllers
à
à
XpressFlow Bus access arbitration
XpressFlow Bus data transfer load
regulation
t Full IP Switching
à
Addresses resolved by SC220
t MAC Address Mapping Table
Related Components:
à
Supports either CAM based or SRAM
based Switching data base
t EA218E – 8-port 10Mbps Ethernet Access Controller
t EA218 – 6-port 10 + 2-port 10/100 Ethernet Access Controller
t EA234 – 4-port 10/100 Fast Ethernet
© 1998 Vertex Networks, Inc.
1
Rev. 4.5 – February
1999
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
