CY7C008/009
CY7C018/019
Document #: 38-06041 Rev. *D
Page 2 of 19
Functional Description
The CY7C008/009 and CY7C018/019 are low-power CMOS
64K, 128K x 8/9 dual-port static RAMs. Various arbitration
schemes are included on the devices to handle situations
when multiple processors access the same piece of data. Two
ports are provided permitting independent, asynchronous
access for reads and writes to any location in memory. The
devices can be utilized as standalone 8/9-bit dual-port static
RAMs or multiple devices can be combined in order to function
as a 16/18-bit or wider master/slave dual-port static RAM. An
M/S pin is provided for implementing 16/18-bit or wider
memory applications without the need for separate master and
slave devices or additional discrete logic. Application areas
include interprocessor/multiprocessor designs, communica-
tions status buffering, and dual-port video/graphics memory.
Each port has independent control pins: chip enable (CE),
read or write enable (R/W), and output enable (OE). Two flags
are provided on each port (BUSY and INT). BUSY signals that
the port is trying to access the same location currently being
accessed by the other port. The interrupt flag (INT) permits
communication between ports or systems by means of a mail
box. The semaphores are used to pass a flag, or token, from
one port to the other to indicate that a shared resource is in
use. The semaphore logic is comprised of eight shared
latches. Only one side can control the latch (semaphore) at
any time. Control of a semaphore indicates that a shared
resource is in use. An automatic power-down feature is
controlled independently on each port by a chip select (CE)
pin.
The CY7C008/009 and CY7C018/019 are available in 100-pin
Thin Quad Plastic Flatpack (TQFP) packages.
Pin Configurations
Note:
5. This pin is NC for CY7C008.
1
3
2
92 91 90
84
85
87 86
88
89
83 82 81
76
78 77
79
80
93
94
95
96
97
98
99
100
59
60
61
67
66
64
65
63
62
68
69
70
75
73
74
72
71
NC
NC
A7R
A8R
A9R
A10R
A15R
A12R
A14R
GND
NC
NC
CE0R
A13R
A11R
NC
NC
CE1R
SEMR
R/WR
OER
GND
GND
NC
A16R
58
57
56
55
54
53
52
51
CY7C008 (64K x 8)
NC
NC
A7L
A8L
A9L
A10L
A15L
A12L
A14L
VCC
NC
NC
CE0L
A13L
A11L
NC
NC
CE1L
SEML
R/WL
OEL
GND
NC
NC
A16L
17
16
15
9
10
12
11
13
14
8
7
6
4
5
18
19
20
21
22
23
24
25
34 35 36
42
41
39 40
38
37
43 44 45
50
48 49
47
46
33
32
31
30
29
28
27
26
CY7C009 (128K x 8)
100-Pin TQFP
(Top View)
[5]
[5]
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