JackOfAll wrote: > Triode, > > Was trying to figure out the logic behind the magic numbers, 23 and 37, > found this.... > > > Code: -------------------- > > > /* > * spdif0_clk will be 454.7MHz divided by ccm dividers. > * > * 44.1KHz: 454.7MHz / 7 (ccm) / 23 (spdif) = 44,128 Hz ~ 0.06% error > * 48KHz: 454.7MHz / 4 (ccm) / 37 (spdif) = 48,004 Hz ~ 0.01% error > * 32KHz: 454.7MHz / 6 (ccm) / 37 (spdif) = 32,003 Hz ~ 0.01% error > */ > -------------------- > >
Good find - pity 7 and 23 are primes.... Is the closest we can get /3 (ccm) /27 (spdif) = 0.55% error for the 88k2 case? For 176400 this means /2 and /20 = 0.69% error [i've not read the datasheet to check these are in range this evening] Means there is real value in having a crystal which is really running at a multiple of the target frequency though, appart from the much lower jitter :) ------------------------------------------------------------------------ Triode's Profile: http://forums.slimdevices.com/member.php?userid=17 View this thread: http://forums.slimdevices.com/showthread.php?t=98544 _______________________________________________ unix mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/unix
