NEC switch - page 32

CHAPTER 2 PIN FUNCTIONS
User’s Manual U12978EJ3V0UD
32
2.2.12 VPP ( µ
µµ
µ PD78F9801 only)
A high voltage should be applied to this pin when the flash memory programming mode is set and when the
program is written or verified.
Handle this pin in either of the following ways.
•Independently connect a 10 kΩ pull-down resistor.
•Switch this pin to be directly connected to the dedicated flash programmer in programming mode or to VSS0 in
normal operation mode using a jumper on the board.
2.2.13 IC (mask ROM version only)
The IC (Internally Connected) pin is used to set the
µ
PD789800 Subseries in the test mode before shipment. In
the normal operation mode, directly connect this pin to the VSS0 pin with as short a wiring length as possible.
If a potential difference is generated between the IC pin and VSS0 pin due to a long wiring length between the IC
pin and VSS0 pin or an external noise superimposed on the IC pin, a user program may not run correctly.
• Directly connect the IC pin to the VSS0 pin.
V SS0
IC
Keep short