Code programming error at 0000

[shahidali55]

Hi miragabe,

In most programmers the MCLR pin will go to about 13 volts only during programming (for just a few seconds after clicking the program button). Are you able to program any other PIC or is it just a particular PIC18F458 giving trouble?

[miragabe]

Hi Shahidali55,
Thanks for your response. Been on this project now for quite some time, and needless to say it has been very frustrating. This is the first PIC I've been given to work with, to get a noritake VFD to come on. When I downloaded the EPIC WIN program and set the board and port voltages to 16V and 5V respectively, the programs uploaded, according to the run response; now it doesnt. The program bar tells me it erases and blank checks, but this error pops up on programming. Is there some kind of limit to the number of times the chip can be programmed? I would think not. I mean like I even rewired everything from scratch according to the program, powered up and still nada.
What do you make of that?
Dave.

[miragabe]

...Another thing, I monitored the MCLR pin while the blankcheck was taking place during programming, and it never got up to the 13 V expected; it stayed at about 5V.

[Demon]

I doubt you have hit a limit count, never heard of one for 16F or 18F PICs. You can always check the datasheet for your particular model. If there is a limit, it will be mentionned.

Totally wild guess, could this have anything to do with a write-protected chip? The first write went well and any further write is refused?

Robert

[shahidali55]

Hi Dave,

According to the datasheet, the number of erase/write cycles this chip can take is 100,000. So this cannot be as to why you are seeing the error.
Can you check if the MCLR pin goes to about 13v on clicking the program button without the chip in the programmer ?

There are three common reasons as to why you could get the error:
1) Damaged serial cable
2) Damaged PIC
3) The PIC was programmed the first time selecting Internal Oscillator with MCLR pin function disable.

The third one may be the one causing the trouble for you.

Also, write protecting a chip will not prevent it from erasing and re-writing.
Just to eliminate any programmer faults, you can try with a new (never programmed before) chip.
If this works, then your programmer does not provide VPP before VDD during programming.