Hi All PICers !

 > Here's another one :) We are going to write serial numbers
 > in all the PICs we program. Because Mchip won't let us read
 > the chip ID from within the PIC software, we decided to do
 > it in the ROM. In the software, there is a lookup table
 > filled with retlw FFs (unprogrammed) During the
 > manufacturing process, the serial number is written in this
 > space as a set number of retlw instructions. The PIC can
 > read this and we can identify each individual chip made by
 > us.

Yea, its a good idea. I use 3 locations, between the reset
vector and the interrupt vector.

   ORG 0
0000   goto START
0001   retlw Loc1
0002   retlw Loc2
0003   retlw Loc3
     ; interrupt subroutine
0004     ............
       retfie
     ;
     START:
         ...............


I implement this feature now in my PICLAB programmer :
automatic increment of 3 byte serial number after each
writing (if serialisation is ON).

   Best Wishes, Alex Torres.
   Kharkov, Ukraine, exUSSR.
   E-Mail To : altor@cook.kharkov.ua   via InterNet
               or 2:461/28             via FidoNet

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