TLV320AIC3268: Inquiries about I2S interface

In most cases, AIC3268 can support the above use case of simultaneously using three I2S buses. However the sampling rates of the three buses should be the same.

In your application, are the BT, and the two AP interfaces having the same sampling rate?

Best Regards.

AP supports up to 384Hz/32-bit and BT specification is not fixed yet, but sampling rate doesn't seem to be a problem because it can be controlled by SW.
I am asking you again to clarify the above questions.

1. When two audio sounds are delivered to audio codec via two I2S Bus (input, AP), one sound can be selected through GPIO, and the selected sound can be output to I2S Bus (output, BT) and HPL/R(Earphone) simultaneously.
(* sampling rates must be the same)
-> right??

2. If I2S Bus is used in TDM mode, can two Audio Sounds be delivered from the AP to Audio Codec through only one I2S Bus?
Also, can I implement the same functions described in number 1 above?
-> possible??

3. If I use number 1 (I2S Bus input 2ea, output 1ea) or 2 (I2S Bus input 1ea, output 1ea, using TDM mode), which pin should I use for I2S communication in Audio codec?

4. If only one of the two sounds delivered by the AP is selected using GPIO, which GPIO pin should I connect to in Audio Codec?

1. Yes, it is possible to select one of two inputs and route it simultaneously to I2S output and HPL/R. A process flow for channel selection and routing has to be built using Purepath Studio using software muxes. Software muxes can be set using I2C writes. I am not sure if there is a way to control the selection using GPIO. Do you need it to be via GPIO? The easy way to enable the selection would be to use coefficient updates using I2C writes.

2. Yes

3. Pins 12,13,14,15 and 17 for WCLK1, DOUT1, DIN1 AND BCLK1 for ASI1 interface. ASI1 interface supports both I2S and TDM interfaces and can support upto 8-channel input and 8-channel output. For ASI2, pins 64,63,59 and 58 can be used as WCLK2, DIN2, BCLK2 and DOUT2.

4. Input selection can be done using I2C writes as described in #1 above.

Thank you for your reply.

First of all, the answer regarding GPIO is thought to be the intention of controlling I2C through GPIO to select one of the two sounds and output the sound simultaneously to BT and Earphone.
(ex. GPIO : 1 -> select Sound#1 with control I2C, GPIO : 0 -> seclect Sound#2 with control I2C)

I'd like to ask you further questions about your answer.

1. In the case of pin 13, which you suggested in your answer 3, it is GPIO2, but did you include it because I requested the GPIO pin number? Or do you have any other purpose?

2. You suggested two I2S BUS (ASI1, ASI2) in the answer number 3, and should I think ASI1 is the input that connects to AP and ASI2 is the output that connects to BT? And the reason why there are two I2S BUS is that TDM mode is applied? If I don't apply TDM mode, shouldn't I use one more I2S BUS?

3. Since AP sends Sound to Audio Codec and outputs it to BT, do I not need to use DOUT1 for ASI1 and DIN2 for ASI2? For your information, there is no mic function.