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µPD6P4B

Data Sheet U13594EJ2V0DS00

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

The program memory of the

µPD6P4B is a one-time PROM of 1002 × 10 bits.

To write or verify this program memory, 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

Supplies voltage when writing/verifying program memory.

Apply +12.5 V to this pin.

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.

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

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

Clock necessary for writing program memory. Connect 4 MHz ceramic resonator to this pin.

3.1 Operating Mode When Writing/Verifying Program Memory

The

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

+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)