X28C64 Datasheet, PDF (4/25 Pages) Xicor Inc. – 5 Volt, Byte Alterable E2PROM

X28C64
DATA Polling I/O₇
Figure 2. DATA Polling Bus Sequence
LAST
WE ^WRITE
CE
OE
VIH
I/O7
HIGH Z
VOL
A0–A12
An
An
An
An
An
VOH
X28C64
READY
An
An
3853 FHD F12
Figure 3. DATA Polling Software Flow
WRITE DATA
DATA Polling can effectively halve the time for writing to
the X28C64. The timing diagram in Figure 2 illustrates
the sequence of events on the bus. The software flow
diagram in Figure 3 illustrates one method of implement-
ing the routine.
WRITES
NO
COMPLETE?
YES
SAVE LAST DATA
AND ADDRESS
READ LAST
ADDRESS
IO7
NO
COMPARE?
YES
X28C64
READY
3853 FHD F13
4