How to connect MCLK of SAI when i.MX7 is slave?

[sidebranch]

Goal is to connect the i.MX7 Synchronous Audio Interface (SAI) to an external master, SIMCON7100.

If the i.MX7 is slave, and the (external) master provides the bitclock (BCLK, configured as input on i.MX7), is it necessary to drive the MCLK on the i.MX7 or can it be unconnected?

If is must be driven, may it be driven with the BCLK?

This is totally unclear from the reference manual. The reference manual only discusses MCLK in the master role.

The SIMCON7100 seems to only provide a bitclock.

(There is a similar question but although it is "assumed answered", there is no correct answer in that thread.)

[igorpadykov]

Hi Leon

>If the i.MX7 is slave, and the (external) master provides the bitclock (BCLK,

>configured as input on i.MX7), is it necessary to drive the MCLK on the i.MX7 or can it be unconnected?

it can be left unconnected, as MCLK is used in master mode only.

Best regards
igor
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[sidebranch]

Hi Igor,

thank you. With the i.MX7 being the slave, and transmitter, the BCLK and SYNC from the codec must be connected to the TX of the i.MX7.

Best regards,

Leon