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PRELIMINARY
Intel 82430NX Chipset
Level II Cache Module Family
CYM74BP54
CYM74P54/55
CYM74SP54/55
Cypress Semiconductor Corporation
3901 North First Street
San Jose
CA 95134
May 1994 – Revised October 1995
408-943-2600
1CYM74SP54/55
Features
Pin-compatible secondary cache module family
Asynchronous (CYM74BP54), synchronous pipelined
(CYM74P54, CYM74P55), or synchronous
(CYM74SP54, CYM74SP55) configurations with pres-
ence and configuration detect pins
Ideal for Intel P54C-based systems with the 82430NX
(Neptune) chipset
Operates at 60 and 66 MHz
Uses cost-effective CMOS asynchronous SRAMs or
high-performance synchronous SRAMs
160-position Burndy DIMM CELP2X80SC3Z48
connector
3.3V inputs/outputs
Functional Description
This family of secondary cache modules is designed for Intel
P54C systems with the 82430NX (Neptune) chipset.
CYM74BP54 is an asynchronous 256-Kbyte cache module
that provides a low-cost, high-performance solution with in-
dustry standard 5V SRAMs and 3.3V level translators for CPU
bus speeds up to 66 MHz. The CYM74BP54 is organized as
32K by 64-bits.
The synchronous modules are available with low-cost syn-
chronous pipelined RAMs or higher performance synchronous
burst RAMs. The synchronous pipelined modules are based
on a 16Kx64 RAM. The CYM74P54 is a 256-KB module while
the CYM74P55 is a 512-KB module. Both are modules without
byte parity.
The CYM74SP54 and CYM74SP55 are synchronous burst
cache modules that provide zero wait-state performance at a
bus speed of 66 MHz. The CYM74SP54 is a 256-Kbyte cache
module with byte parity. The CYM74SP55 is a 512-Kbyte
cache module with byte parity.
Multiple ground pins and on-board decoupling capacitors en-
sure high performance with maximum noise immunity.
All components on the cache modules are surface mounted
on a multi-layer epoxy laminate (multifunctional) substrate.
The contact pins are plated with 150 micro-inches of nickel
covered by 10 micro-inches of gold flash.
Intel is a registered trademark of Intel Corporation.
A
Logic Block Diagram - CYM74BP54
LA
17
-LA
5
WE
0
WE
1
WE
2
WE
3
A
A
A
D
D
D
D
CE
OE
CE
OE
CE
OE
CE
OE
WE
4
WE
5
WE
6
WE
7
A
A
A
A
D
D
D
D
CE
OE
CE
OE
CE
OE
CE
OE
CE
0
OE
0
WE
0
-WE
3
OE
1
WE
4
-WE
7
D
0
-D
7
D
8
-D
15
D
16
-D
23
D
24
-D
31
D
32
-D
39
D
40
-D
47
D
48
-D
55
D
56
-D
63
32K x 8
32K x 8
32K x 8
32K x 8
32K x 8
32K x 8
32K x 8
32K x 8
A
4–0
-A
3–0
A
4–1
-A
3–1
A
17
-A
7
ADDRESS LATCH
LE
CALE
A
74BP54–1
A
6–0
-A
5–0
CE
1