The requirement of grounding the PGM pin is generally what I have read as the solutions/suggestions where people are running into difficulties in programming a PIC using HV mode. A floating PGM pin would easily put the PIC into LV programming mode(if the PIC's LV mode has been enabled in the config) and then one might not be able to place it in HV programming mode.
How true is that I really don't know because I always ground the PGM pin during programming. Perhaps others can put in their comments here.
bryan1 said:
So now I'm abit confused :shock:
Don't be. What if I tell you that some new PIC comes with LV programming mode enabled by default?