Another cause of Presence Rate mismatch is due to the required oversampling ratio.
When the Presence Rate is equal or greater than 128 kHz, the master clock is set to
128Fs. It is set to 256Fs for the other presence rates.
The oversampling ratio applies to both the I2S input and output interfaces. This means
that when using such high sampling rates, it must be used on every active channels.
This applies to both PLL and external clock operation.
4.4. Incompatible Clock Gear
The Clock Gear incompatibility only happens when the PLL operation is selected. When
the Clock Gear is too low to allow proper PLL operation, the “!” symbol is displayed after
OPR and IPR to indicate that the PLL could not be set.
I2S >ASRC24>SB>SDO2
P01234567 OPR!96k
IIOO---- IPR!96k
Err: ClkGear too low
Running on external clocks will not have such limitations. However, the clock gear must
be such that there is enough bandwidth in the SLIMbus to fit the desired data channels.
SLIMbus Audio Bridge User Manual V0,9 - Draft Version
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