Dataman Forum

I am building an Elektor Electronics project and I have a strange result programming the pic chip. The source hex code is from their site
http://www.elektor-electronics.co.uk/dl/dl.htm
and then May 2002 and then RS232-485 Software.
I am using their hex file 020003.hex and programming the chip. I keep getting verify fail, BUT doing a compare is all OK.
Looking at hex dumps of chip verses disk file it seems to be location 1FFE which changes from F9 to F8 when I do a compare. Once this changes on its own by doing a compare, verify then passes but I still have F8 in the chip but the hex file was originally F9.
Why does this happen ? What is the differance between verify and compare ? Does this actually matter ?

Paul Van Gelder

Hi,

Could you send me the hex file that you are using, I have had a look on their website but I could not find it.

Neil

Thanks for your help, I emailed the files to you this morning to [email protected]

Paul Van Gelder

Hi,

OK, basically the difference in the hex code and the code you have burnt onto the chip is due to the various features of the chip and how they have been set. If you check the datasheet for the PIC 16C54 the address 1FFE > 1FFF is the location of the configuration word

Lookign at the PIC 16C54 datasheet the address 1FFE to 1FFF is the location of the configuration word.

So your problem is that your chip has already been programmed to LP in the factory or the chip has been programmed to LP by accident.

Hope this helps,

Neil

Thanks for the pointer to the problem.

It makes sense now, in the projects part list they specify an HS chip, which I brought. But their hex file is for an XT chip. In the Chip HS is bit setting 10 and XT is 01. Hence when I blew 01 on top of an existing 10, I ended up with 00. 00 is LP as you wrote.

I have now blown another chip but manually changed to HS setting before programming, that left the setting at HS and all is OK.

Thank you for all your help.

Paul Van Gelder