As Weddington, Eric wrote: > Joerg, do you have any idea how much this function is actually used?
I know that it's at least been used in Atmel's IEEE 802.15.4 stack. But sure, you never know how many people use them. It's been there since the early days of avr-libc, so you can guess someone wrote it nine years ago since they had a need for it. > I think it would be a good idea to support xmega users too. They are already well supported by _crc_xmodem_update(), they just need to be told. ;-) As I wrote, it uses the very same polynomial, just the opposite order: CCITT: 0x8408 = 0b1000010000001000 Xmodem: 0x1021 = 0b0001000000100001 Btw., if I run the table-driven algorithm of RFC1171 on the string "HELLO" (with an initial value of 0xffff), I also get 0x258a, which is at least a proof that the function serves well for the purpose it claims to serve ... -- cheers, J"org .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-) _______________________________________________ AVR-libc-dev mailing list AVR-libc-dev@nongnu.org https://lists.nongnu.org/mailman/listinfo/avr-libc-dev
