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Programmable Asynchronous Initialize
Register
GENERAL DESCRIPTION
The WS57C45 is an extremely High Performance 16K UV Erasable Registered CMOS RPROM. It is a direct
drop-in replacement for such devices as the AM27S45 and CY7C245.
To meet the requirements of systems which execute and fetch instructions simultaneously, an 8-bit parallel data
register has been provided at the output which allows RPROM data to be stored while other data is being
addressed.
An asynchronous initialization feature has been provided which enables a user programmable 2049th word to be
placed on the outputs independent of the system clock. This feature can be used to force an initialize word or
provide a preset or clear function.
A further advantage of the WS57C45 over Bipolar PROM devices is the fact that it utilizes a proven EPROM
technology. This enables the entire memory array to be tested for switching characteristics and functionality after
assembly. Unlike devices which cannot be erased, every WS57C45 RPROM in a windowed package is 100%
tested with worst case test patterns both before and after assembly.
PIN CONFIGURATION
TOP VIEW
Chip Carrier
NC
CERDIP/Plastic DIP/
Flatpack
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
O
0
O
1
O
2
GND
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
V
CC
A
8
A
9
A10
INIT/V
PP
OE/OE
S
CP/PGM
O
7
O
6
O
5
O
4
O
3
A
5
A
6
A
7
V
CC
A
8
A
9
A
4
A
3
A
2
A
1
A
0
NC
O
0
4 3 2
28 27 26
1
5
25
6
24
7
23
8
22
9
21
10
20
11
19
12 13 14 15 16 17 18
O
1
O
2
NC O
3
O
4
O
5
A
10
INIT/V
PP
OE/OE
S
CP/PGM
NC
O
7
O
6
GND
PRODUCT SELECTION GUIDE
PARAMETER
Set Up Time (Max)
Clock to Output (Max)
WS57C45-25
25 ns
12 ns
WS57C45-35
35 ns
15 ns
WS57C45-45
45 ns
25 ns
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