[SOLVED] Can't Reprogram PIC16F628A with Pickit2

[melc]

Hi there,

This is the right solution for a closed thread named "Can't Reprogram PIC16F628A with Pickit2".

The PICKIT2 (or PICKIT3) is reading the ID of the PIC16F628 which is located at the address 2006h. The correct value you should see at address 2006h is 07C0h. If by mistake that value was deleted and replaced with FFFFh, PicKIT2 will not be able to write again the PIC16F628 because it see it as invalid device.

The workaround I did was writing the ID address using a classic ICProg software + parallel HW programmer.
After that, PiCKit read the ID and see the PIC16F628 as a valid device.

This is happening if trying to program very old PICs with newer programmers....

 

[betwixt]

You shouldn't be able to delete or reprogram the device ID bytes, they are hard coded at 0x2006. Other addresses in the range 0x2000 to 0x200F should be accessible but other software even attempting to reprogram, let alone change it seems unlikely.

Brian.

 

[melc]

You shouldn't be able to delete or reprogram the device ID bytes, they are hard coded at 0x2006. Other addresses in the range 0x2000 to 0x200F should be accessible but other software even attempting to reprogram, let alone change it seems unlikely.

Brian.

Brian, you shuldn't, but I've just did. On PIC16F628 (not A) that location is scrambled by Pickit2 during bad programming. Once is erased ( reading the memory content with other software such IcProg) you can see the content FFFF. Icprog is able to rewrite that location, once is written Pickit 2 see the PIC16F628.

A good workaround is to modify the configuration file for the PIC16F628 and move it in the no ID group (PIC16F84, PIC16C84). Fortunately I had just to burn a PIC16F628 chip for a very old application on which I've used PIC16C84 (15 years old or so).