µPD61P24

19

17.2

Program Memory Writing Procedure

The program memory is written at high speed in the following procedure.

(1) Pull down the pins not used to GND via resistor. Keep the CLK pin low.

(2) Supply 5 V to the VDD pin. Keep the VPP pin low.

(3) Wait for 10

µs, and supply 5 V to the VPP pin.

(4) Set the mode in which the program memory address is cleared to 0, by using the mode setting pins.

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

(6) Set the program inhibit mode.

(7) Write data in the 1-ms write mode.

(8) Set the program inhibit mode.

(9) Set the verify mode. If the data has been correctly written, proceed to (10). If not, repeat (7) through (9).

(10) Additional writing of (Number of times data has been written in (7) through (9): X)

× 1 ms

(11) Set the program inhibit mode.

(12) Input a pulse four times to the CLK pin to update the program memory address (+1).

(13) Repeat (7) through (12) until the data is written to the last address.

(14) Set the mode in which the program memory address is cleared to 0.

(15) Change the voltage on the VDD and VPP pins to 5 V.

(16) Turn off power supply.

Program memory writing steps (2) through (12) are illustrated below.

Write

Verify

Additional write

Address

increment

Repeat X times

MD3

MD2

MD1

MD0

D0-D7

CLK

GND

VDD

VDD

VDD+1

GND

VDD

VPP

VPP

Data input

Data output

Data input

Hi-Z

Hi-Z

Hi-Z

Hi-Z

Reset