CHAPTER 14
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µµ
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PD78F9801
User’s Manual U12978EJ3V0UD 195
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.
<VPP pin>
In normal operation mode, input 0 V to the VPP pin. In flash memory programming mode, a write voltage of 10.0 V
(TYP.) is supplied to the VPP pin, so perform either of the following.
(1) Connect a pull-down resistor (RVPP = 10 kΩ) to the VPP pin.
(2) Use the jumper on the board to switch the VPP pin input to either the writer or directly to GND.
A VPP pin connection example is shown below.
Figure 14-4. VPP Pin Connection Example
PD78F9801
VPP
Connection pin of dedicated flash programmer
Pull-down resistor (RVPP)
µ
<Serial interface pin>
The following shows the pins used by the serial interface.
Serial Interface Pins Used
3-wire serial I/O S I10, SO10, SCK10
Pseudo-3-wire P12, P11, P10
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.