I'm trying to program a 16C84 with a low cost PARALLAX programmer
and have some trouble:
1/ I'm obliged to program 3 or 5 times the chip to have
the oscillator programmed for CRYSTAL and not RC
2/ I have the programmed chip (SMD), then sold it onto the board.
I connect RB6,RB7, MCLR and VCC to the programmer in order to modify
the program. Problem is as the chip is programmed for Crystal oscillator
the programmer as many difficulties to read and program it.
Does anybody know if it's necessary the oscillator section run properly
to re-program a 16C84 ?
Does somebody have the same problem with a parallax programmer ?
In a message dated 97-03-17 11:40:53 EST, you write:
<<
Hi all,
I'm trying to program a 16C84 with a low cost PARALLAX programmer
and have some trouble:
1/ I'm obliged to program 3 or 5 times the chip to have
the oscillator programmed for CRYSTAL and not RC
2/ I have the programmed chip (SMD), then sold it onto the board.
I connect RB6,RB7, MCLR and VCC to the programmer in order to modify
the program. Problem is as the chip is programmed for Crystal oscillator
the programmer as many difficulties to read and program it.
Does anybody know if it's necessary the oscillator section run properly
to re-program a 16C84 ?
Does somebody have the same problem with a parallax programmer ?
Regards,
Philippe.
>>
Philippe,
The system my company makes has 14 PIC16F84s on a single control board. They
are all SMD chips and are all programmed through an in-circuit programming
connector. I use the Parralax programmer to accomplish this. I have
experienced the same type of problem that you describe here. Our problem was
caused by the Ocsillator (We use one 10mhz oscilator to drive all 14 pics).
The Microchip spec. say that there can be no oscillation on the crystal
inputs durring the first three transitions of the serial clock used for
programming. We now put the oscillator in a socket and insert it after
programming is complete. This seems to solve all of our little quirky
problems.
Hope this helps.
Dave Duley
V.P. DreiTek Inc.
At 17:20 17/03/97 -0800, you wrote:
>I'm trying to program a 16C84 with a low cost PARALLAX programmer
>and have some trouble:
> 1/ I'm obliged to program 3 or 5 times the chip to have
>the oscillator programmed for CRYSTAL and not RC
> 2/ I have the programmed chip (SMD), then sold it onto the board.
>I connect RB6,RB7, MCLR and VCC to the programmer in order to modify
>the program. Problem is as the chip is programmed for Crystal oscillator
>the programmer as many difficulties to read and program it.
>
>Does anybody know if it's necessary the oscillator section run properly
>to re-program a 16C84 ?
>Does somebody have the same problem with a parallax programmer ?
I've tried the in-circuit programming with a DIY "LUDIPIPO" programmer,
and I've found that the extra power consummed by the PIC while it is in the
circuit (with the oscilator running) make it impossible to re-program. May
be the Parallax Programmer works in a simmilar way (I dont'k know), then
you need a programmer with its own power supply (just what I'm trying to
build now ).
good lucky.
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At 05:20 PM 3/17/97 -0800, you wrote:
>Hi all,
>
>I'm trying to program a 16C84 with a low cost PARALLAX programmer
>and have some trouble:
> 1/ I'm obliged to program 3 or 5 times the chip to have
>the oscillator programmed for CRYSTAL and not RC
> 2/ I have the programmed chip (SMD), then sold it onto the board.
>I connect RB6,RB7, MCLR and VCC to the programmer in order to modify
>the program. Problem is as the chip is programmed for Crystal oscillator
>the programmer as many difficulties to read and program it.
>
>Does anybody know if it's necessary the oscillator section run properly
>to re-program a 16C84 ?
>Does somebody have the same problem with a parallax programmer ?
I used the schematic Microchip had in the data sheet with the Parallax
programmer, and it works very well. Perhaps you have RB6 and RB7 in
contention with another device on your target board?
You DON't want the oscillator running at this time. You can accomplish
that by simply grounding pin OSC1.
Andy
==================================================================
Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
Hardware & Software for Industry & R/C Hobbies
"Go fast, turn right, and keep the wet side down!"
==================================================================
At 17.20 17-03-1997 -0800, you wrote:
>Hi all,
>
>I'm trying to program a 16C84 with a low cost PARALLAX programmer
>and have some trouble:
> [ ... ]
> Problem is as the chip is programmed for Crystal oscillator
>the programmer as many difficulties to read and program it.
>
>Does anybody know if it's necessary the oscillator section run properly
>to re-program a 16C84 ?
>Does somebody have the same problem with a parallax programmer ?
>
>Regards,
> Philippe.
Hi Philippe
I've had a similar problem with a 16C74 and a Smart-ICEPIC, a
programmer/simulator/emulator from RAM Technology Systems, Dorset, England.
The PIC was not programmed reliably when the oscillator was running. I was
told that it's a problem with PIC device, not the programmer.
Try disconnecting the crystal while programming, the device don't need it.
It worked for me and the 16C74. I don't know about the 16C84 but it may work
for you too. Bonne chance.
idls.izarbel.tm.fr
