On-Board Pin Processing - NEC switch User Manual

14.1.3 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.
<V pin>
PP
In normal operation mode, input 0 V to the V
(TYP.) is supplied to the V
PP
(1) Connect a pull-down resistor (RV
(2) Use the jumper on the board to switch the V
A V pin connection example is shown below.
PP
<Serial interface pin>
The following shows the pins used by the serial interface.
3-wire serial I/O
Pseudo-3-wire
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.
CHAPTER 14
pin. In flash memory programming mode, a write voltage of 10.0 V
PP
pin, so perform either of the following.
= 10 kΩ) to the V
PP
pin input to either the writer or directly to GND.
PP
Figure 14-4. V Pin Connection Example
PP
µ
PD78F9801
Connection pin of dedicated flash programmer
V
PP
Pull-down resistor (RV
Serial Interface
User's Manual U12978EJ3V0UD
µ µ µ µ PD78F9801
pin.
PP
)
PP
Pins Used
SI10, SO10, SCK10
P12, P11, P10
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