Common notes
NEC uPD78Fxxxx microcontrollers
This interface corresponds with NEC User's manual of selected
target device. This User's manual describes requirements for
target system with In-system programming device and ISP
programmer. Following signal are used for In-system
programming of uPD78Fxxxx microcontrollers.
RESET\ reset device
VPP switch device to programming mode
SI serial data input
SO serial data output
SCK serial data clock
VDD power supply
VSS ground
When device is programmed, pin VPP is driven to
approximately 10V. SI, SO, SCK pins are used by device for
In-system programming, therefore target system mustn’t affect
these signals during In-system programming to avoid
programming error. As well, RESET pin should be isolated (or
not affected) during programming the device.
ELNEC’s recommended circuit for uPD78Fxxxx:
ISP connector target device target system
reset circuit
R2
22k
R3
22k
VSS
C1
22n
G
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