SLAS763C August 2012 – October 2018 PCM5121 , PCM5122
PRODUCTION DATA.
The classic example here is running a 12-MHz Master clock for a 48-kHz sampling system. Given the clock tree for the device (shown in Figure 63), a non-audio clock rate cannot be brought into the SCK to the PLL in master mode. Therefore, the PLL source must be configured to be a GPIO pin, and the output brought back into another GPIO pin.
The clock flow through the system is shown in Figure 65. The newly-generated SCK must be brought out of the device on a GPIO pin, then brought into the SCK pin for integer division to create BCK and LRCK outputs.
NOTE
Pullup resistors must be used on BCK and LRCK in this mode to ensure the device does not go into sleep mode.
A code example for configuring this mode is provided in the PCM5242 data sheet (SLASE12).