UVEPROM
SMJ27C256
Austin Semiconductor, Inc.
FUNCTIONAL BLOCK DIAGRAM*
EPROM 32,768 x 8
10
9
8
7
6
5
4
A0
A1
A2
A3
A4
A5
A6
A7
A8
11
12
13
15
16
17
18
19
DQ0
A
A
A
A
A
A
A
A
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
3
25
24
21
0
A
A9
32,767
A10
A11
A12
A13
A14
E\
23
2
26
27
20
22
[PWR DWN]
&
G\
EN
* This symbol is in accordance with ANSI/IEEE std 91-1984 and IEC Publication 617-12.
OPERATION
The seven modes of operation for the SMJ27C256 are listed in Table 1. The read mode requires a single 5V supply. All
inputs are TTL level except for VPP during programming (13V for SNAP! Pulse), and (12V) on A9 for signature mode.
TABLE 1. OPERATION MODES
MODE*
FUNCTION
OUTPUT
DISABLE
VIL
PROGRAM
INHIBIT
VIH
SIGNATURE MODE
(PINS)
READ
STANDBY PROGRAMMING VERIFY
VIL
VIL
E\ (20)
G\ (22)
VIL
VIL
VCC
VCC
X
VIH
X
VIL
VIH
VPP
VCC
X
VIH
VIL
VPP
VCC
X
X
VPP
VCC
X
VIH
VCC
VCC
X
VCC
VCC
VPP (1)
VCC
VCC
X
VCC (28)
A9 (24)
A0 (10)
VID
VIL
VID
VIH
X
X
X
X
X
X
CODE
DQ0-DQ7
(11-13, 15-19)
Data Out High-Z
High-Z
Data In
Data Out
High-Z
MFG
97
DEVICE
04
* X can be VIL or VIH.
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
SMJ27C256
Rev. 1.0 9/01
2