Dennis Crawley wrote: > I've tried four CRC8 routines in Keil C51 for a 8051 core: Hi Dennis, Thanks for trying this out. The 30 instruction Keil rendition of the crc_bits() routine would probably be closer to 20 instructions if the 8051 had a "bit test and skip" type instruction like the PIC. Regards, Scott -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist