Dear all,
I have a problem in power up PIC18F1320. The internal 8MHz oscillator has been used. It can been power up and show 2Mhz in RA6 by Regulated 5V power supply. However, it can't power up by USB port from PC. Also, the Fail-Safe Clock Monitor and Internal External Switch Over Mode are enabled. I have found the only difference between the regulated power supply and power from USB port is the rise up time. The regulated power supply rise up time is much much longer than USB port. Please advice.
Thank you