On Fri, May 3, 2013 at 9:52 AM, Joerg Wunsch <invalid.nore...@gnu.org> wrote: > Update of patch #7485 (project avr-libc): > > Status: None => In Progress > Assigned to: None => joerg_wunsch > > _______________________________________________________ > > Follow-up Comment #1: > > Curious, what's the reference for naming it after CCITT? > > _______________________________________________________ > > Reply to this item at: > > <http://savannah.nongnu.org/patch/?7485> > > _______________________________________________ > Nachricht gesendet von/durch Savannah > http://savannah.nongnu.org/ >
I wrote the patch to support LTC6803 chip that only gives the polynomial in question and no name. I guess it shouldn't be named that way, the CCITT recommendation include a XOR at the end. It is sometime referenced as CRC-ATM and CRC-ITU Page 6(PDF page 12) http://www.itu.int/rec/T-REC-I.432.1-199902-I/en http://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-I.432.1-199902-I!!PDF-E&type=items The CRC-ROHC as the same polynomial but not the same start value. RFC 3095 gives the polynomial as for IR and IR-DYN packet http://tools.ietf.org/html/rfc3095#section-5.9.1 This site, which have a catalogue of CRC, gives no suffix to the name (CRC-8). http://reveng.sourceforge.net/ http://reveng.sourceforge.net/crc-catalogue/1-15.htm Since all three CRC use the same polynomial, here is my proposition to cover all three cases: - rename to _crc8_update - Caller shall chose it's initial value(0x00 for simple use and CCITT/ITU/ATM or 0xFF for ROHC) - Caller apply xor at the end if needed. - Modify doc accordingly If we agree on that, I'll resubmit a patch asap. _______________________________________________ AVR-libc-dev mailing list AVR-libc-dev@nongnu.org https://lists.nongnu.org/mailman/listinfo/avr-libc-dev
