UVEPROM
AS27C256
Austin Semiconductor, Inc.
OPERATION
The seven modes of operation for the AS27C256 are listed in Table 1. The read mode requires a single 5V supply.
All inputs are TTL level except for VPP during programming (12.75V for FLASHRITE Pulse), and (12V) on A9
for signature mode.
TABLE 1. OPERATION MODES
MODE*
FUNCTION
OUTPUT
DISABLE
PROGRAM
INHIBIT
SIGNATURE MODE
(PINS)
READ
STANDBY PROGRAMMING VERIFY
VIL
VIL
E\
G\
VIL
VIL
VIL
VIH
VIH
X
VIL
VIH
VPP
VCC
X
VIH
VIL
VPP
VCC
X
VIH
X
X1
VCC
X
X1
VCC
X
X1
VCC
VCC
VPP
VCC
A9
VPP
VCC
X
VCC+/-.3V
2
2
X
X
VID
VID
A0
X
X
X
X
X
VIL
VIH
CODE**
DQ0-DQ7
Data Out High-Z
High-Z
Data In
Data Out
High-Z
MFG
01h
DEVICE
10h
1For normal standby & read operation, VPP is Don't Care X.
2 VID = 12V +/- .5V
NOTES:
* X can be VIL or VIH
** Die is AMD. User can program on benchtop programmer by selecting AM27C256 from the device
type selection menu.
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
AS27C256
Rev. 2.0 7/06
3
MICROSS [ MICROSS COMPONENTS ]
