NEC PD78F9488 - Manual (Page 324)

CHAPTER 19 FLASH MEMORY VERSION
324
User’s Manual U15331EJ4V1UD
19.1.3 On-board pin processing
When performing programming on the target system, provide a connector on the target system to connect the
dedicated flash programmer.
An on-board function that allows switching between normal operation mode and flash memory programming mode
may be required in some cases.
PP
pin>
In normal operation mode, input 0 V to the V
PP
pin. In flash memory programming mode, a write voltage of 10.0 V
(TYP.) is supplied to the V
PP
pin, so perform either of the following.
(1) Connect a pull-down resistor (RV
PP
= 10 k Ω) to the V
PP
pin.
(2) Use the jumper on the board to switch the V
PP
pin input to either the programmer or directly to GND.
A V
PP
pin connection example is shown below.
Figure 19-4. V
PP
Pin Connection Example
PD78F9488,
PD78F9489
V PP
Connection pin of dedicated flash programmer
Pull-down resistor (RV
PP
)
µ
µ
The following shows the pins used by the serial interface.
Serial Interface Pins Used
3-wire serial I/O SI20, SO20, SCK20
3-wire serial I/O with handshake SI20, SO20, SCK20, P11 (HS)
UART RxD20, TxD20
When connecting the dedicated flash programmer to a serial interface pin that is connected to another device on-
board, signal conflict or abnormal operation of the other device may occur. Care must therefore be taken with such
connections.