AM625: Connecting AM6254 to ADV7511 Audio Port

Hello Kris, 

Thank you for the query.

Kris Ganev said:

Do we need to supply external oscillator with audio clock frequency like 12.288 MHz or the audio clock can be accurately generated with the processor PLL/dividers with the standard 25.0 MHz main crystal?

I’m also fairly sure the AM62x device will not be able to generate a 12.288MHz clock.  I suggest you to use the clock tree tool to better understand their clocking options.  If not, you will need to use an external LVCMOS clock source to generate this clock.

I am reviewing the other inputs.

Regards,

Sreenivasa

Hello Kris, 

Kris Ganev said:

We will be using Analog Devices HDMI transmitter ADV7511  (hardware design support files) with the TI AM6254 processor.

The ADV7511 has I2S port and S/PDIF port. How do we connect the AM625 audio port (I2S) so that PCM is supported. Do we need to connect the AM625 I2S to the SPDIF (Input) and the SPDIF MCLK (clock) in addition to the I2S interface.

Can the AM625 I2S pins be shared between the two ADV7511 interfaces or just I2S interface will suffice for PCM?

I could not find detailed information on the ADV7511.

I suspect you have the required information to review.

I will update with any information i receive.

Regards,

Sreenivasa

Hello Kris, 

Refer additional inputs i received:

So if the SOC is the master for BCLK and FSYNC. It cannot provide exact 48KHz unless an external reference is provided for MCASP for generating the required output freq
For I2S only 3 lines needs to be connected to the SOC. (Ignoring the HCLK in case it is supplied externally to the SOC)
BCLK
FSYNC
DATA
Same I2S pins can be shared across ADV7511 instances.
Provided they are configured correctly (if one ADV7511 is master, other should be slave also the SOC should be slave OR if SOC is master both ADV7511 should be slave )

Regards,

Sreenivasa

Hello Kris, 

Refer additional inputs i received:

The ADV7511 has I2S port and S/PDIF port. How do we connect the AM625 audio port (I2S) so that PCM is supported. Do we need to connect the AM625 I2S to the SPDIF (Input) and the SPDIF MCLK (clock) in addition to the I2S interface.

The McASP does not natively support S/PDIF…..

The I2S connection would be fine.   I do not know if the ADV7511 does the S/PDIF conversion – documentation is not great, at least the docs I was able to download.

Can the AM625 I2S pins be shared between the two ADV7511 interfaces or just I2S interface will suffice for PCM?

I theory, connecting two  ADV7511 should be fine if the each have their own serializer (I2S mode) and can share the same bit and word clocks.    However, there is concern over signal quality of the bit clock due to layout and the track capacitance affecting the SOC output drive strength.

Do we need to supply external oscillator with audio clock frequency like 12.288 MHz or the audio clock can be accurately generated with the processor PLL/dividers with the standard 25.0 MHz main crystal?

For precise clock frequencies, best to use an external source.  PLL1 and PLL2 are used for other peripherals.

Regards,

Sreenivasa

The ADV7511 information is linked in my initial question and here - ADV7511  (hardware design support files) 

Hello Kris, 

Thank you.

I cannot access a detailed data sheet.

Can you please provide the link.

Regards,

Sreenivasa