I have a dsPIC33EP512MU810 connected to a custom made board for reading biosensors. I have been programming the PIC no problem up until just now. I added a little extra circuitry to the board and now the PLL initialisation code causes the PIC to halt. If I do not initialise PLL, the code runs fine. Can external hardware affect whether the PLL engages? I am a bit lost as to why this is happening now!

Dan

 

righto, found the problem, if was a dodgy connection to the Vcap pin on the pic! did not allow PLL to engage but slower operations were fine. makes sense really. i hope this info comes in useful to other people in the future!