NEC PD750008 - Manual (Page 251)

231
CHAPTER 9 WRITING TO AND VERIFYING PROGRAM MEMORY (PROM)
The timing for steps (2) to (12) is shown below.
V
PP
V DD
V PP
V
DD +1
V
DD
V
DD
X1
P40-P43
P50-P53
MD0
(P30)
MD1
(P31)
MD2
(P32)
MD3
(P33)
Data input Data output Data input
Write Verify Additional write
Address
increment
Repeat x times