help reading a 16C621A..

[d_mc_a]

Hi,

I'm a bit of a amateur when it comes to PIC programmer. I'll explain my situation. I have a CCTV system at home with 2 x 4 channel Video capture cards. Its a PC based CCTV system running windows XP and a simple video server that is recording 6 camera inputs from around my house. It's a little bit dated and hardware has been swapped and upgraded many times in it. My problem is that on of the camera's was recently struck by lightning and it fried one of the video capture cards along with a few other things. I eventually managed to replace all the damaged hardware as well as the video capture card but the software I'm using doesn't allow me to use the new card. I've noticed a removable PIC ( 16C621A ) on the working card that is not present on the new card. I imagine this PIC contains some kind of Identification info for the software running on the PC so I planned on buying a PIC programmer that would allow me to read the working chip and write it to a blank chip of the same type. I tried swapping in the old, damaged cards PIC but is clearly not working. I bought a couple of blank 16C621A's and also a K150 USB PIC Programmer.

I have managed to install the programmer on a PC here and it is detected perfectly by the MicroPro programming software when I try to read from the original chip, it returns all zero's and the read data. All I am doing is plugging the PIC into the 40 pin interface on the programmer in the correct location and orientation.

Is there any PIC guru here that would be nice enough to help?


Thanks,

[meo_udon]

That chip has code protection bits set. It hard to read but in the China can read it. Only 1% to read it.

[d_mc_a]

Ok, thanks for the info. I guess I'll have to try and source the chips somewhere else.

[d_mc_a]

Its been a while but I've only started looking at this again recently since I now have access to my college resources. I bought a number of blank 16C621A chips and attempted to read the eeprom using a programmer that I have access to in the college. It appears to read correctly but the data that is read appears to be far to small to be correct. I flashed the read data to one the blank chips and they both itslef and the original appear identical but the new eeprom doesn't work. Clearly you are correct about the protection bits. I'm just bumping the thread to see if anyone else has any info on how I could bypass this read protection.

Thanks,

[Horsedorf]

You might want to make sure the configuration bits are set correctly for the pic. Also, the pic that you read from, might be using the internal oscilator which means it might have to be properly trimmed to make it run at 4mhz or whatever internal clock rate the thing is running at. Depending on what the pic is doing in the system, the code may not be very large at all, a few hundred bytes or less.