CYM1836
128K x 32 Static RAM Module
constructed from four 128K x 8 SRAMs in SOJ packages
mounted on an epoxy laminate board with pins. Four chip se-
lects (CS1, CS2, CS3, CS4) are used to independently enable
the four bytes. Reading or writing can be executed on individ-
ual bytes or any combination of multiple bytes through proper
use of selects.
Features
• High-density 4-megabit SRAM module
• 32-bit standard footprint supports densities from 16K
x 32 through 1M x 32
• High-speed CMOS SRAMs
— Access time of 15 ns
• Low active power
Writing to each byte is accomplished when the appropriate
Chip Select (CS) and Write Enable (WE) inputs are both
LOW. Data on the input/output pins (I/O) is written into the
memory location specified on the address pins (A0 through
A16).
— 2.6W (max.) at 20 ns
• SMD technology
• TTL-compatible inputs and outputs
• Low profile
Reading the device is accomplished by taking the Chip Select
(CS) LOW while Write Enable (WE) remains HIGH. Under
these conditions, the contents of the memory location
specified on the address pins will appear on the data in-
put/output pins (I/O).
— Max. height of 0.57 in.
• Small PCB footprint
— 0.78 sq. in.
The data input/output pins stay at the high-impedance state
when write enable is LOW or the appropriate chip selects are
HIGH.
• AvailableinSIMM, ZIPformat. SIMM suitableforvertical
or angled sockets.
Two pins (PD0 and PD1) are used to identify module mem-
ory density in applications where alternate versions of the
JEDEC-standard modules can be interchanged.
Functional Description
The CYM1836 is a high-performance 4-megabit static RAM
module organized as 128K words by 32 bits. This module is
Logic Block Diagram
Pin Configuration
ZIP/SIMM
Top View
PD −OPEN
0
PD −OPEN
1
A − A
GND
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
0
16
PD
I/O
17
2
4
6
8
0
PD
1
OE
WE
0
I/O
8
I/O
9
I/O
10
I/O
I/O
1
2
3
I/O
V
10
12
14
16
18
20
22
24
26
28
30
32
I/O
11
CC
A
A
0
128K x 8
SRAM
I/O − I/O
7
0
7
A
1
4
4
4
4
A
8
A
2
A
9
4
I/O
12
I/O
CS
1
I/O
I/O
13
14
I/O
5
I/O
6
I/O
7
I/O
15
128K x 8
SRAM
GND
I/O − I/O
8
15
WE
A
15
A
14
CS
2
CS
1
CS
CS
CS
2
3
4
CS
33
35
37
39
41
43
45
47
49
51
53
55
57
59
61
63
4
CS
3
16
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
NC
A
128K x 8
SRAM
OE
I/O
GND
I/O − I/O
16
23
24
I/O
16
17
18
19
I/O
25
I/O
26
I/O
I/O
I/O
I/O
27
A
3
A
A
10
11
A
4
128K x 8
SRAM
I/O − I/O
A
5
24
31
A
12
A
13
V
CC
A
6
I/O
20
I/O
21
I/O
22
I/O
23
I/O
28
1836–1
I/O
I/O
29
30
I/O
31
GND
1836–2
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
February 15, 1999