46
CYM1846
512K x 32 Static RAM Module
constructed from four 512K x 8 SRAMs in SOJ packages
mounted on an epoxy laminate substrate. Four chip selects are
used to independently enable the four bytes. Reading or writ-
ing can be executed on individual bytes or any combination of
multiple bytes through proper use of the chip selects.
Features
• High-density 16-megabit SRAM module
• 32-bitstandardfootprintsupportsfrom16Kx32through
1Mx32
• High-speed SRAMs
— Access time of 12 ns
• Low active power
The CYM1846 is designed for use with standard 72-pin SIMM
socket and ZIP footprint. The pinout is compatible with the
64-pin JEDEC ZIP/SIMM module family (CYM1821,
CYM1831, CYM1836, and CYM1841) and the 72-pin
CYM1851. Thus, a single motherboard design can be used to
accommodate memory depth ranging from 16K words
(CYM1821) to 1024K words (CYM1851). The standard SIMM
can be used in Angled SIMM sockets and is available with
either tin-lead or 10 micro-inches of gold flash on the edge
contacts.
— 4.4W (max.) at 12 ns
• Compatible with CYM1821, CYM1831, CYM1836,
CYM1841, and CYM1851 JEDEC modules
• Available in 72-pin ZIP or SIMM/Angled SIMM
Functional Description
Presence detect pins (PD0 – PD3) are used to identify module
memory density in applications where modules with alternate
word depths can be interchanged.
The CYM1846 is a high-performance 16-megabit static RAM
module organized as 512K words by 32 bits. This module is
Logic Block Diagram
Pin Configuration
ZIP/SIMM
Top View
PD – OPEN
0
PD – OPEN
1
NC
PD
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
PD – GND
NC
2
2
4
6
8
2
PD
PD – OPEN
3
3
GND
PD
0
PD
1
I/O
0
A – A
I/O
0
18
OE
WE
8
I/O
1
10
12
14
16
18
20
22
24
26
28
30
32
19
I/O
9
I/O
2
I/O
10
I/O
3
I/O
11
V
CC
A
0
A
7
A
1
A
8
A
512Kx8
SRAM
2
I/O – I/O
0
7
A
9
I/O
8
8
8
8
12
I/O
4
I/O
13
I/O
5
I/O
14
CS
1
I/O
6
I/O
15
I/O
7
GND
WE
33
35
A
512Kx8
SRAM
15
A
I/O – I/O
14
8
15
34
36
CS
2
CS
1
CS
17
37
39
41
43
45
47
49
51
53
55
57
59
61
63
65
67
69
71
4
CS
CS
2
3
38
40
42
44
46
48
50
52
54
56
58
60
62
64
66
68
70
72
A
A
16
OE
GND
I/O
512Kx8
SRAM
24
I/O – I/O
I/O
16
23
16
I/O
25
I/O
17
I/O
26
I/O
18
I/O
27
I/O
19
CS
3
A
3
A
10
A
4
A
11
A
5
512Kx8
SRAM
A
I/O – I/O
12
24
31
V
CC
A
13
A
6
I/O
20
I/O
28
I/O
21
I/O
CS
4
I/O
29
22
I/O
I/O
30
23
I/O
31
GND
A
18
NC
NC
NC
Cypress Semiconductor Corporation
Document #: 38-05276 Rev. **
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
Revised March 15, 2002
