x28c64 Intersil Corporation, x28c64 Datasheet - Page 5

• Manufacturer Part Number: x28c64
• Description: 5 Volt, Byte Alterable E2prom
• Manufacturer: Intersil Corporation

X28C64
The Toggle Bit I/O
Figure 4. Toggle Bit Bus Sequence
Figure 5. Toggle Bit Software Flow
I/O 6
WE
CE
OE
WRITE
* Beginning and ending state of I/O 6 will vary.
LAST
FROM ADDR n
LOAD ACCUM
ACCUM WITH
LAST WRITE
COMPARE
COMPARE
6
ADDR n
X28C64
READY
OK?
YES
*
NO
V OH
3853 FHD F15
V OL
5
The Toggle Bit can eliminate the software housekeeping
chore of saving and fetching the last address and data
written to a device in order to implement DATA Polling.
This can be especially helpful in an array comprised of
multiple X28C64 memories that is frequently updated.
Toggle Bit Polling can also provide a method for status
checking in multiprocessor applications. The timing
diagram in Figure 4 illustrates the sequence of events on
the bus. The software flow diagram in Figure 5 illustrates
a method for polling the Toggle Bit.
HIGH Z
*
X28C64
READY
3853 FHD F14