Cirrus Logic CDB42438 - Manual (Page 21)

CDB42438
DS646DB2 21
5.7.2 DSP MCLK (MCLK_M/S)
Default = 0
0 - DSP MCLK is a slave to the MCLK bus.
1 - DSP MCLK masters MCLK bus.
Function:
Enables/disables the external DSP MCLK output buffer on the MCLK bus.