Hi Dave,

Which PICs are you talking about? Most PICs cannot read their own program
memory,so they cannot perform such a checksum test. I am not very familiar
with the new PICs which have come out in the last few months. If I remember
correctly, however, they CAN read program memory. If you are using one of
these PICs, you can store the checksum either in the data EEPROM, or in the
program memory (which is also EEPROM). If you did the latter, you could use
a CRC routine,which is nice because the checksum itself is considered a
part of the data being checked,and the CRC polynomical division will yield
a remainder of zero when performed on data which is terminated in a valid
checksum,otherwise,it will return a non-zero number.

Sean

At 03:13 PM 9/17/99 -0230, you wrote:
>Hi all,
>
>I've got to do a checksum on program memory and compare it to a known
>checksum.  I want to store the known checksum on the PIC.  Is there
>anywhere I can store it besides in the program memory or those ID
>locations?
>
>And if i did store it in those ID locations, how do I read it?
>Thanks
>
>DAve
>
|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
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