CAT28LV256 Datasheet, PDF (8/10 Pages) Catalyst Semiconductor – 256K-Bit CMOS PARALLEL E2PROM

CAT28LV256
DATA Polling
DATA polling is provided to indicate the completion of
write cycle. Once a byte write or page write cycle is
initiated, attempting to read the last byte written will
output the complement of that data on I/O7 (I/O0–I/O6
are indeterminate) until the programming cycle is com-
plete. Upon completion of the self-timed write cycle, all
I/O’s will output true data during a read cycle.
Figure 7. DATA Polling
ADDRESS
Toggle Bit
In addition to the DATA Polling feature, the device can
determine the completion of a write cycle, while a write
cycle is in progress, by reading data from the device.
This results in I/O₆ toggling between one and zero. Once
the write is complete, however, I/O₆ stops toggling and
valid data can be read from the device.
CE
WE
OE
I/O7
Figure 8. Toggle Bit
WE
tOEH
DIN = X
tOE
tWC
DOUT = X
tOES
DOUT = X
28LV256 F10
CE
tOEH
tOE
OE
I/O6
(1)
tWC
Note:
(1) Beginning and ending state of I/O₆ is indeterminate.
tOES
(1)
28LV256 F11
Doc. No. 25040-00 4/01 P-1
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