Configuration Register Write Protection

Torello · Joined: 29 Sep 2006 Posts: 120

Hi,

Can't find much about this topic.
When flashed the PIC with this bit set, does that mean you can't change the configuration bit -never ever- after?

I'm able to reprogram such a PIC. But even with my new 'unprotected' fuse setting, i'm not able to readback the PIC.

Regards,
Edwin.

FvM · Joined: 27 Aug 2008 Posts: 2337 Location: Germany

In case of doubt, consult your PIC's datasheet.
Different chips have different capabilities in this regard, which one are you refering to?

Generally, readout protection is a separate configuration fuse for any PIC device, as far as I know.

Torello · Joined: 29 Sep 2006 Posts: 120

I did consult the datasheet pic18lf4685. Searched on configuration register write protect bit and only found the bit location the register. No description so far..

I understand that readout protection are other bits, but they don't seem to change when I reprogram the device (with everything unprotected), because I still can't readback the device.

My thoughs are that this configuration write protect bit is keeping all bits 'locked'. Or ccsload is acting strange...

Regards,
Edwin

FvM · Joined: 27 Aug 2008 Posts: 2337 Location: Germany

CCS has fuses to set the protection features. They have names according to the Microchip configuration bits, e.g. WRTC for the config protection.
As far as remember, they are working correctly with PIC18.

I don't understand the "can't readback" point. But I'm mostly using MPLAB, so I'm not that familiar with ccsload.

Torello · Joined: 29 Sep 2006 Posts: 120

With readback I mean read from chip; read the memory program code from the chip into a hex file.

The problem is in the current version of CCS-Loader: v4019. In v4012 it was working OK.

Status:
- reported to CCS; bug acknowedged
- they are working on a fix.

Thanks for you help.
Regards,
Edwin