Hi! This could be the origin of the problem. Here's the bit codes of the machine instructions which load a literal value to a file select register:
18f26k22: LFSR 1110 1110 00ff kkkk - 1111 0000 kkkk kkkk18f27k42: LFSR 1110 1110 00ff kkkk - 1111 00kk kkkk kkkk 18f27q43: LFSR 1110 1110 00ff kkkk - 1111 00kk kkkk kkkk k22 has only 12 bit deep FSR, while the ones with the larger RAM have 14 bit. The low byte is the same on all chips, but the high bits are arranged differently. While on k22 bits 11,10,9 and 8 are in the lowest nibble of the first word, that nibble on the larger chips hold bits 13,12,11 and 10. Bits 9 and 8 are in locations which were defined as zero on k22. This means, if the compiler only generates the k22 form of the command, banks are skipped. Only banks 0,4,8,12... are addressed. Unpopulated RAM locations on the k42 start at 0x2000. Divided by four due to the lost bits that region would be adressed from 0x0800 on, which is exactly what the test program showed. Greets,Kiste -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/57246174.5045899.1605268813743%40mail.yahoo.com.
