Daren X wrote:
> Hi Everyone,
> After doing more testing on my ICSP circuit I strongly believe that the
> PIC isn't going into programming mode once VIHH is applied to MCLR. It
> simply goes along and executes code as normal. Has anyone seen similar
> behaviour?
>
> The pic (16f877) has a max232 connected to its Tx and Rx lines, is
> running a 20MHz crystal with 2 15pf caps.
>
> It also has a 4x20 LCD screen connected to RD1-7, in 4 bit mode.
>
> Regards,
> Daren

There's more to it than that. Look up the programming specs for the
device. I think the PGM Data and PGM clock pins must be in a certain
state as it rises from VCC to VP.

--Bob

--
              --------------
                Bob Axtell
        PIC Hardware & Firmware Dev
          http://beam.to/baxtell
              1-520-219-2363

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