SC220 ZARLINK [Zarlink Semiconductor Inc], SC220 Datasheet - Page 14

• Manufacturer Part Number: SC220
• Description: XpressFlow 2020 Ethernet Routing Switch Chipset
• Manufacturer: ZARLINK [Zarlink Semiconductor Inc]

XpressFlow-2020 Series –
Ethernet Switch Chipset
2.2 Local Memory (Control Buffer Memory) Interface
t
t
t
2.2.1
© 1998 Vertex Networks, Inc.
1999
Uses industry standard Synchronous Burst SRAM (Pipe-lined Mode)
Provides 4 individual Byte Write Enable controls
Supports back to back Read or Write operations
Supports 64k x 32, 128k x 32, or 256k x 32 chips up to maximum 2M bytes
Pin Description
L_D[31:0]
L_A[18:2]
L_A[19] /
L_WE[3]#
L_WE[2:0]#
L_OE[3:0]#
L_BWE[3:0]# CMOS
L_ADSC#
L_CLK
Symbol
P
R
E
I/O-TS
CMOS
Output
CMOS
Output
CMOS
Output
CMOS
Output
Output
CMOS
Output
CMOS
Output
L
Type
TTL
I
M
Name & Functions
Local Memory Data Bus Bit [31:0] – a 32-bit synchronous data bus.
Local Memory Address Bus Bit [18:2] – Bit [17:2] of a synchronous ad-
dress bus. The memory address is sampled when L_CS# is enabled
and L_ADSC# is asserted.
Local Memory Address Bus Bit [19] or Local Memory Write Chip Select
[3] – Depends on memory configuration, this pin can be used as the
Local Memory Address Bit [19] or as the Local Memory Write Chip
Select [3].
Local Memory Write Chip Select [2:0] – allows up to write one of the 4
banks of memory.
Local Memory Read Chip Select [3:0] – allows up to read one of the 4
banks of memory.
Local Memory Byte Write Enable [3:0] – use to write individual bytes.
Local Memory Controller Address Status – to load a new address.
Local Memory Clock – a synchronous clock to memory devices.
I
N
A
R
Y
I
13
N
F
O
R
M
A
T
I
XpressFlow Engine
O
N
Rev. 4.5 – February
SC220