CAT28C17A

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6

DEVICE OPERATION

Read

Data stored in the CAT28C17A is transferred to the data

bus when WE is held high, and both OE and CE are held low.

The data bus is set to a high impedance state when either CE

or OE goes high. This 2−line control architecture can be used

to eliminate bus contention in a system environment.

Ready/BUSY (RDY/BUSY)

The RDY/BUSY pin is an open drain output which

indicates device status during programming. It is pulled low

during the write cycle and released at the end of

programming. Several devices may be OR−tied to the same

RDY/BUSY line.

Figure 4. Read Cycle

ADDRESS

DATA OUT

DATA VALID

DATA VALID

HIGH−Z

CE

OE

WE

ADDRESS

DATA VALID

HIGH−Z

Figure 5. Byte Write Cycle [WE Controlled]

CE

OE

WE

RDY/BUSY

DATA OUT

DATA IN