12f675

young · Joined: 24 Jun 2004 Posts: 285

I had a big trouble with 12f675, I could not download program to it, or after I download program to it several times, I can not download program to it anymore, what is wrong with it, are there any way to get the chip back to work?

Mark · Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA

What do you mean that you cannot download to it? Does it give an error? Or does the program just not run? I have seen a "glitch" where the oscal value gets erased. If you use the internal oscillator, this would be a problem since the code is expecting a return there. Without it, it just keeps looping because the erased location is treated as a NOP and the program counter wraps.

Guest · Posted: Wed Aug 04, 2004 5:55 am

It was give back program failed error?

Mark · Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA

It means that on a couple of occasions the OSCAL value got erased and would not get reprogrammed. All of the programmers that I know of prevent you from programming that location. When you say program failed error what do you mean? That the verification failed? Or something else.

Guest · Posted: Wed Aug 04, 2004 6:30 am

after executing the write program command, an windows error msg pop up say
" Program failed
Program: 1014 errors
EEPROM: 128 errors
IDs : 4 errors"

Guest · Posted: Wed Aug 04, 2004 6:33 am

Mark · Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA

Like I said, it was a "glitch". Something went wrong in the process. Microchip (and others) has taken a step to prevent the novice user from erasing the OSCAL value. When a chip is erased, they read this value and store it, do a bulk erase and then reprogram this value back. Something went wrong, something unexcepected, a small "glitch" and the value did not get reprogrammed back. It does not sound like your problem. This would just make the program not function correctly. Not give you errors when programming.