The PCM codec is designed to perform transmit
encoding analog/digital (A/D) conversion, receive
decoding digital/analog (D/A) conversion, and transmit
and receive filtering for voice-band communications
systems. The device operates in either the 15-bit linear
or 8-bit companded (u-law or A-Law) mode, which is
selectable through the I2C interface. The PCM codec
generates its own internal clocks from a 2.048-MHz
master clock input.