Other Parts Discussed in Thread: PCM4222
Hi,
We're currently assessing different high-end audio ADCs EVM, and after reading the PCM4222EVM guide here http://www.ti.com/lit/ug/sbau124/sbau124.pdf I'm a bit confused if the EVM is matching our needs.
Context
We are using a multi-channel USB audio interface https://www.minidsp.com/products/usb-audio-interface/usbstreamer that have an I2S interface.
This interface only works in "Master mode", so that the chips connecting to it through the I2S header needs to follow the clocks on MCK, BCK and LRCK.
As far as I understand, the PCM4222 supports slave mode, and this can be configured on the EVM by following on the guide 2.7.2 Audio Serial Port, Table 8 by putting SW3 to HI.
As far as I understand from the schematics, SN74ALVC245PW will just ignore any external clock source if SM is indicating slave mode, meaning that Master clock source switch SW6, as in 2.5 Master Clock Source Table 3 is irrelevant when SW3 is HI.
As far as I understand, the PCM4222 doesn't need MCK since it's not going to derive BCK and LRCK from it. On the connector J6, MCK wouldn't pass the buffer that is supposed to be used the other way around anyway.
Question
Are those assumptions correct:
- Is Clock select SW6 configuration irrelevant when Slave/Master mode select SW3 is HI (Slave)?
- Are only BCK and LRCK needed to be connected to the I2S header?
Thanks for any information on that matter,
Raphael
