NEC NEC PD78081(A), User Manual

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CHAPTER 15
µ
PD78P083
15.2.3 PROM reading procedure
PROM contents can be read onto the external data bus (D0 to D7) using the following procedure.
(1) Fix the RESET pin low, and 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) 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.
Figure 15-6. PROM Read Timing
Address Input A0-A14
CE (Input)
OE (Input)
D0-D7
Hi-Z
Data Output
Hi-Z