E2O0014-27-X2
隆 Semiconductor
MSM81C55-5RS/GS/JS
隆 Semiconductor
2048-Bit CMOS STATIC RAM WITH I/O PORTS AND TIMER
This version: Jan. 1998
MSM81C55-5RS/GS/JS
Previous version: Aug. 1996
GENERAL DESCRIPTION
The MSM81C55-5 has a 2k-bit static RAM (256 bytes) with parallel I/O ports and a timer. It uses
silicon gate CMOS technology and consumes a standby current of 100 micro ampere, maximum,
while the chip is not selected. Featureing a maximum access time of 400 ns, the MSM81C55-5
can be used in an MSM80C85AH system without using wait states. The parallel I/O consists
of two 8-bit ports and one 6-bit port (both general purpose).
The MSM81C55-5 also contains a 14-bit programmable counter/timer which may be used for
sequence-wave generation or terminal count-pulsing.
FEATURES
鈥?High speed and low power achieved with silicon gate CMOS technology
鈥?256 words x 8bits RAM
鈥?Single power supply, 3 to 6 V
鈥?Completely static operation
鈥?On-chip address latch
鈥?8-bit programmable I/O ports (port A and B)
鈥?TTL Compatible
鈥?RAM data hold characteristic at 2 V
鈥?6-bit programmable I/O port (port C)
鈥?14-bit programmable binary counter/timer
鈥?Multiplexed address/data bus
鈥?Direct interface with MSM80C85AH
鈥?40-pin Plastic DIP (DIP40-P-600-2.54): (Product name: MSM81C55-5RS)
鈥?44-pin Plastic QFJ (QFJ44-P-S650-1.27): (Product name: MSM81C55-5JS)
鈥?44-pin Plastic QFP (QFP44-P-910-0.80-2K): (Product name: MSM81C55-5GS-2K)
FUNCTIONAL BLOCK DIAGRAM
Port A
IO/M
A
AD
0 - 7
CE
ALE
RD
WR
RESET
Timer
C
Port C
6
PC
0 - 5
256
樓
8
Static
RAM
B
Port B
8
PB
0 - 7
8
PA
0 - 7
TIMER IN
TIMER OUT
V
CC
(+5 V)
GND (0 V)
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