IBM nec pd78p081(a2) User Manual

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PROM contents can be read onto the external data bus (D0 to D7) using the following procedure.

(1) Fix the RESET pin low, and supply +5 V to the V

PP

 pin.  Unused pins are handled as shown in paragraph,

(2) “PROM programming mode” in section 1.5 Pin Configuration (Top View).

(2) Supply +5 V to the V

DD

 and V

PP

 pins.

(3) Input the address of data to be read to pins A0 through A14.

(4) Read mode is entered.

(5) Data is output to pins D0 through D7.

The timing for steps (2) through (5) above is shown in Figure 15-6.

Address Input

A0-A14

CE (Input)

OE (Input)

D0-D7

Hi-Z

Data Output

Hi-Z