μPD75P308

3.2 PROGRAM MEMORY WRITE PROCEDURE

The program memory write procedure is as follows. High-speed program memory write is possible.

(1)Ground the unused pins through pull-down resistors. The X1 pin must be low.

(2)Supply 5 V to the VDD and VPP pins.

(3)Wait for 10 microseconds.

(4)Set program memory address 0 clear mode.

(5)Supply 6 V to the VDD pin and 12.5 V to the VPP pin.

(6)Set program inhibit mode.

(7)Write data in 1-millisecond write mode.

(8)Set program inhibit mode.

(9)Set verify mode. If data has been written connectly, proceed to step (10). If data has not yet been written, repeat steps (7) to (9).

(10)Write additional data for (the number of times data was written (X) in steps (7) to (9)) times

1milliseconds.

(11)Set program inhibit mode.

(12)Supply a pulse to the X1 pin four times to update the program memory address by 1.

(13)Repeat steps (7) to (12) to the last address.

(14)Set program memory address 0 clear mode.

(15)Change the voltages of VDD and VPP pins to 5 V.

(16)Turn off the power supply.

Steps (2) to (12) are illustrated below.

X-time repetition

Write Verify Additional data write

Address

increment

VPP

VPP

VDD

VDD+1

VDD

VDD

 

 

 

 

 

 

X1

 

 

P40-P43

Data

Data input

 

Data input

output

P50-P53

 

MD0

(P30)

MD1

(P31)

MD2 (P32)

MD3 (P33)

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NEC PD75P308 user manual Program Memory Write Procedure, VDD+1