CAT28C512_04 Datasheet, PDF (8/12 Pages) Catalyst Semiconductor – 512K-Bit CMOS PARALLEL EEPROM

CAT28C512/513
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.
Toggle Bit
In addition to the DATA Polling feature of the CAT28C512/
513, the device offers an additional method for determin-
ing the completion of a write cycle. While a write cycle is
in progress, reading data from the device will result in I/
O₆ toggling between one and zero. However, once the
write is complete, I/O₆ stops toggling and valid data can
be read from the device.
Figure 7. DATA Polling
ADDRESS
CE
WE
tOEH
tOE
OE
tOES
tWC
I/O7
DIN = X
DOUT = X
D _OUT = X
Figure 8. Toggle Bit
WE
CE
OE
I/O6
tOEH
tOE
(1)
tOES
(1)
tWC
Note:
(1) Beginning and ending state of I/O₆ is indeterminate.
Doc. No. 1007, Rev. F
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