Don Taylor <PICLIST@mitvma.mit.edu> wrote:

> Summary: 16F877 Pic acts like it isn't even running at power up.
> Why?

    No idea, Don... But, damn, you sure know how to ask for help.

    Your message should be posted somewhere on the piclist.com
    website as the ideal toward which all requests for help should
    strive.  Even Olin at his MOST cantankerous wouldn't be able to
    find fault with your post.

> /* processor control bits, configuring the hardware before startup
> 11             disable flash memory code protection
>   1            disable in-circuit-debug
>    1           unimplemented
>     1          disable flash memory write protect
>      1         disable eeprom protect
>       0        disable in-circuit low voltage programming
>        0       disable brown-out reset of the processor
>         11     disable flash memory code protection
>           1    disable 72ms power up delay
>            0   disable watchdog timer
>             11 resistor-capacitor oscillator
> 11111100111011=0x3F33 */
> __CONFIG(0x3F33);

    Your comments match the ones and zeroes, but the bits don't add
    up to 0x3F33; if you really want the power-up delay disabled,
    you'll need to use 0x3FB3.  I'd be astonished if this made any
    difference whatsoever, though.

> I've got the IC-Prog 1.05 software and the PG2B programmin
> hardware. It happily recognizes the part, programs it, confirms the
> program and will do this again and again.

    My only suggestion -- it's not a particularly good one, but
    you've sorta eliminated all the others -- is to double- and
    triple-check that you're ACTUALLY programming the part with the
    code you want.  Is there a chance that you're burning the PIC
    with the wrong program?

> All the port pins sit at zero volts, but not pulled down hard enough
> to sink current and, say, light a led.

    The PIC is really acting as though it isn't programmed... If you
    have another programmer (preferably different from your
    programming hardware/software -- maybe a Microchip programmer
    borrowed from your local distributor?), you could use it to read
    out the contents of the PIC and see if it really contains what
    you think it should.

    -Andy

=== Andrew Warren -- aiw@cypress.com
=== Principal Design Engineer
=== Cypress Semiconductor Corporation
===
=== Opinions expressed above do not
=== necessarily represent those of
=== Cypress Semiconductor Corporation

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