21.4.2.6.2 Host Mode Clocking and MCLK
The SPI module as a host has the ability to generate BCLK and LRCK by internally
generating using PBCLK (MCLKEN = 0
). The SPI module can generate the
clock for external codec devices using the reference output, REFCLKO, function (see
Figure 21-29), although
some codecs may have the ability to generate their own MCLK from a crystal to provide
accurate audio sample rates. Figure 21-30 shows that
the REFCLKO clock can be used as MCLKIN by the codec.
Figure 21-30 shows the interface between an SPI client and a codec host, deriving the clock from the MCLK input interface.