10

µPD66P04B

Data Sheet U13596EJ2V1DS00

3. WRITING AND VERIFYING ONE-TIME PROM (PROGRAM MEMORY)

The program memory of the

µPD66P04B is a one-time PROM of 1002 × 10 bits.

To write or verify this one-time PROM, the pins shown in Table 3-1 are used. Note that no address input pin

is used. Instead, the address is updated by using the clock input from the CLK pin.

Table 3-1. Pins Used to Write/Verify Program Memory

Pin Name

Function

VPP

Supplies voltage when writing/verifying program memory.

Apply +12.5 V to this pin.

VDD

Power supply.

Supply +6 V to this pin when writing/verifying program memory.

CLK

Inputs clock to update address when writing/verifying program memory.

By inputting pulse four times to CLK pin, address of program memory is updated.

MD0-MD3

Input to select operation mode when writing/verifying program memory.

D0-D7

Inputs/outputs 8-bit data when writing/verifying program memory.

OSCIN, OSCOUT

Clock necessary for writing program memory. Connect a resistor (R = 47 k

Ω) and a capacitor

(C = 27 pF) to these pins.

3.1 Operating Mode When Writing/Verifying Program Memory

The

µPD66P04B is set in the program memory write/verify mode when +6 V is applied to the VDD pin and +12.5

V is applied to the VPP pin after the

µPD66P04B has been in the reset status (VDD = 5 V, VPP = 0 V) for a specific

time. In this mode, the operating modes shown in Table 3-2 can be set by setting the MD0 through MD3 pins. Connect

all the pins other than those shown in Table 3-1 to GND via pull-down resistor.

Table 3-2. Setting Operation Mode

Setting of Operating Mode

Operation Mode

VPP

VDD

MD0

MD1

MD2

MD3

+12.5 V

+6 V

H

L

H

L

Clear program address to 0

L

H

H

H

Write mode

L

L

H

H

Verify mode

H

×

H

H

Program inhibit mode

×: don’t care (L or H)