CHAPTER 3 PIN FUNCTIONS
User’s Manual U14826EJ5V0UD
37
3.2.7 V
DD
This pin supplies positive power.
3.2.8 V
SS
This pin is the ground potential pin.
3.2.9 V
PP
(
µ
PD78E9860A, 78E9861A only)
A high voltage should be applied to this pin when the EEPROM programming mode is set and when the program
is written or verified.
Perform either of the following pin handling.
•
Individually connect a 10 k
Ω
pull-down resistor.
•
Connect to a dedicate flash programmer in the programming mode and directly to V
SS
in the normal operation
mode by using a jumper on the board.
If the wiring length between the V
PP
and V
SS
pins is too long or if external noise is superimposed on the V
PP
pin,
your program may not be executed correctly.
3.2.10 IC (mask ROM version only)
The IC (Internally Connected) pin is used to set the
µ
PD789860 and 789861 to test mode before shipment. In
normal operation mode, directly connect this pin to the V
SS
pin with as short a wiring length as possible.
If a potential difference is generated between the IC pin and the V
SS
pin due to a long wiring length between these
pins or an external noise superimposed on the IC pin, the user program may not run correctly.
•
Directly connect the IC pin to the V
SS
pin.
V
SS
IC
Keep short