AT27C256R
Block Diagram
Absolute Maximum Ratings*
Temperature Under Bias ................ -55°C to +125°C
Storage Temperature...................... -65°C to +150°C
Voltage on Any Pin with
Respect to Ground......................... -2.0V to +7.0V
(1)
Voltage on A9 with
Respect to Ground ...................... -2.0V to +14.0V
(1)
V
PP
Supply Voltage with
Respect to Ground....................... -2.0V to +14.0V
(1)
*NOTICE: Stresses beyond those listed under “Absolute Maxi-
mum Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of the
device at these or any other conditions beyond those indi-
cated in the operational sections of this specification is not
implied. Exposure to absolute maximum rating conditions
for extended periods may affect device reliability.
Note:
1. Minimum voltage is -0.6V dc which may undershoot
to -2.0V for pulses of less than 20 ns. Maximum out-
put pin voltage is V
CC
+ 0.75V dc which may over-
shoot to +7.0V for pulses of less than 20 ns.
Operating Modes
Mode \ Pin
Read
Output Disable
Standby
Rapid Program
(2)
PGM Verify
(2)
Optional PGM Verify
(2)
PGM Inhibit
(2)
Product Identification
(4)
CE
V
IL
V
IL
V
IH
V
IL
X
(1)
V
IL
V
IH
V
IL
OE
V
IL
V
IH
X
(1)
V
IH
V
IL
V
IL
V
IH
V
IL
Ai
Ai
X
(1)
X
(1)
Ai
Ai
Ai
X
(1)
A9 = V
H (3)
A0 = V
IH
or V
IL
A1 - A14 = V
IL
V
PP
V
CC
V
CC
V
CC
V
PP
V
PP
V
CC
V
PP
V
CC
Outputs
D
OUT
High Z
High Z
D
IN
D
OUT
D
OUT
High Z
Identification
Code
Notes: 1. X can be V
IL
or V
IH
.
2. Refer to Programming characteristics.
3. V
H
= 12.0
±
0.5V.
4. Two identifier bytes may be selected. All Ai inputs
are held low (V
IL
), except A9 which is set to V
H
and A0
which is toggled low (V
IL
) to select the Manufacturer’s Identi-
fication byte and high (V
IH
) to select the Device Code byte.
3-127
ATMEL [ ATMEL CORPORATION ]
