4
AT29C256
0046P–FLASH–10/04
PRODUCT IDENTIFICATION:
and manufacturer and may be accessed by a hardware operation. For details, see
Operating Modes or Product Identification.
The product identification mode identifies the device
DATA POLLING:
gram cycle. During a program cycle an attempted read of the last byte loaded will result
in the complement of the loaded data on I/O7. Once the program cycle has been com-
pleted, true data is valid on all outputs and the next cycle may begin. DATA polling may
begin at any time during the program cycle.
The AT29C256 features DATA polling to indicate the end of a pro-
TOGGLE BIT:
determining the end of a program or erase cycle. During a program or erase operation,
successive attempts to read data from the device will result in I/O6 toggling between
one and zero. Once the program cycle has completed, I/O6 will stop toggling and valid
data will be read. Examining the toggle bit may begin at any time during a program
cycle.
In addition to DATA polling the AT29C256 provides another method for
OPTIONAL CHIP ERASE MODE:
software code. Please see Software Chip Erase application note for details.
The entire device can be erased by using a six-byte
Absolute Maximum Ratings*
Temperature Under Bias................................ -55
°
C to +125
°
C
*NOTICE:
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.
Storage Temperature..................................... -65
°
C to +150
°
C
All Input Voltages (including NC Pins)
with Respect to Ground...................................-0.6V to +6.25V
All Output Voltages
with Respect to Ground.............................-0.6V to V
CC
+ 0.6V
Voltage on OE
with Respect to Ground...................................-0.6V to +13.5V