UPD78F9500MA-CAC-A Datasheet, PDF (233/342 Pages) Renesas Technology Corp – 8-Bit Single-Chip Microcontrollers

CHAPTER 16 FLASH MEMORY
16.6.3 RESET pin
If the reset signal of the dedicated flash memory programmer is connected to the RESET pin that is connected to
the reset signal generator on the board, signal collision takes place. To prevent this collision, isolate the connection
with the reset signal generator.
If the reset signal is input from the user system while the flash memory programming mode is set, the flash
memory will not be correctly programmed. Do not input any signal other than the reset signal of the dedicated flash
memory programmer.
Figure 16-6. Signal Collision (RESET Pin)
78K0S/KU1+
RESET
Signal collision
Dedicated flash programmer
connection signal
Reset signal generator
Output pin
In the flash memory programming mode, the signal output by the reset
signal generator collides with the signal output by the dedicated flash
programmer. Therefore, isolate the signal of the reset signal generator.
16.6.4 Port pins
When the flash memory programming mode is set, all the pins not used for flash memory programming enter the
same status as that immediately after reset. If external devices connected to the ports do not recognize the port
status immediately after reset, the port pin must be connected to VDD or VSS via a resistor.
The state of the pins in the self programming mode is the same as that in the HALT mode.
16.6.5 Power supply
Connect the VDD pin to VDD of the flash memory programmer, and the VSS pin to VSS of the flash memory
programmer.
User’s Manual U18172EJ3V0UD
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