On Wed, February 15, 2012 7:46 am, Wouter van Ooijen wrote:
>> 1. When using LVP the programmer provides DATA (PGD)  and CLOCK (PGC)
>> signals and few others.
>>      I like to know if the PGC is only for the serial data processing
>> or it drives ALL the
>>      PIC internal hardware modules (including the programme/data memory
>> clock)  that takes part at the programing process.
>
> PICs that have only an external clock option (xtal, extclck, etc) can be
> programmed without such components in place, so I guess the PGC *must*
> be the clock for everything, because at that moment there is no other
> clock.

Programming on a PIC via PGC/PGD is done via an internal state machine,
The only clock source necessary is PGC. PGC does not drive the core or
peripheral clocks.  Depending on the timing of all the programming lines
with respect to power-up- if the part being re-programmed (such as the
start of a debug session) it is possible that the part can start executing
code in the brief time after MCLR is released, before it is asserted again
in the programming cycle.



Matt Bennett
Just outside of Austin, TX
30.51,-97.91

The views I express are my own, not that of my employer, a large
multinational corporation that you are familiar with.
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