D17133CS datasheet(196/289 Pages) NEC

196 / 289 page

CHAPTER 17

ONE-TIME PROM WRITING/VERIFYING

181

17.3 WRITING PROCEDURE OF PROGRAM MEMORY

The program memory can be written at high speeds in the following procedure.

(1)

Pull down the unused pins to GND. (XOUT pin is open.) Mask the CLK pin low.

(2)

Apply 5 V to the VDD pin. Make VPP pin low.

(3)

Wait for 10

µs. Then, apply 5 V to VPP pin.

(4)

Set the program memory address 0 clear mode using mode selector pins.

(5)

Apply 6 V to VDD and 12.5 V to VPP.

(6)

Set the program inhibit mode.

(7)

Write data in mode for 1 ms writing.

(8)

Set the program inhibit mode.

(9)

Set the verify mode (MD0-MD3=LLHH). If the program has been correctly written, proceed to (10).

If not, repeat (7) through (9).

(10) Additional writing of (number of times (

×) the program has been written in (7) through (9)) × 1ms.

(11) Set the program inhibit mode.

(12) Input four pulses to the CLK pin to update the program memory address by one.

(13) Repeat (7) through (12) until the last address in programmed.

(14) Set the program memory address 0 clear mode.

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

(16) Turn off the power.

Figure 17-1 shows the procedures of (2) through (12).

D17133CS Datasheet(PDF) 196 Page - NEC