For this PCB there will be a voltage regulator that provides 3.3V from 12 VDC. There will also be a 6-pin connector for doing In system programming via SPI. The SPI programmer is going to be an Arduino Uno, which will provide its target uC (and the whole board) with Vcc. My question is how should I route the Vcc on the board ? Should there be any kind of decoupling (jumper ?) between the voltage regulator to be used when in ISP mode ?
Went to How should power be supplied for in-system programming? but - not quite what I am looking to know.