NEC PD75402A - Manual (Page 21)

CHAPTER 2. PIN FUNCTIONS
10
CHAPTER 2. PIN FUNCTIONS
The
µ
PD75402A operates by the pin functions in the normal operating mode.
For the
µ
PD75P402’s pin functions, the 2 modes of the normal operating mode (
µ
PD75402A mode) and the PROM
mode are available.
The operating mode switches according to the V
PP
pin level as shown in the table below.
V
PP
Operating Mode
Low level (GND potential) Normal operating mode
High level (+5 V) PROM read mode
High level (+12.5 V) PROM write/verify mode
PROM mode