28C256 查看數據表（PDF） - Catalyst Semiconductor => Onsemi

零件编号

产品描述 (功能)

生产厂家

28C256

32K-Bit Parallel E2PROM

Catalyst Semiconductor => Onsemi 

CAT28C256

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 CAT28C256,

the device offers an additional method for determining

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

OE

I/O7

Figure 8. Toggle Bit

WE

tOEH

DIN = X

tOE

tWC

DOUT = X

tOES

DOUT = X

28C256 F10

CE

tOEH

tOE

OE

I/O6

(1)

Note:

(1) Beginning and ending state of I/O6 is indeterminate.

tWC

tOES

(1)

28C256 F11

Doc. No. 25020-0A 2/98

8

Share Link: