Dear all,
I'm in the process of looking for an affordable stereo audio DAC that can easily be interfaced using an NXP LPC11U24, either through the LPC's on-board serial interfaces or good ol' bitbanging (but then of course in bursts, leaving enough idle time to actually generate the audio data).
The PCM175x series looks like an excellent candidate, but I'm puzzled by the sheer number of different clocks that those DAC's serial interfaces require, which apparently all need to run at constant frequency and in sync. Usually, you'd think that the data interface can be clocked independently of the system clock if the data rate is sufficiently low. After digging through the PCM's datasheet, the only way (that I can think of) to interface a standard USART or SSP as they are found, for instance, in AVR8 and LPC uCs would be to externally divide the bit clock by 16 to obtain LRCK. Certainly there are better ways I'm not aware of. Any ideas/hints?
Thanks,
Matthias