TAS5825M: Question of TAS5825 Audio Format Support in PPC3

Wayne Chen (ex FAE)

Part Number: TAS5825M

Hi Sirs,

We are supporting customer to generate TAS5825 CFG to support 16 bit left-justified format. We can bring up the TAS5825 in this audio mode with 0x33 = 0x30 update by Direct I2C or Register Map:

However, we found that the PPC3's system integration page does not dump 0x33 data. We can rework CFG by adding those two lines manually, however, we don't know the correct location to insert them. We found that TAS5825 can decode LJ data properly only if we add them to the last line of the CFG (please refer to the enclosed CFG before and after reworked).

----------------
w 98 00 00
w 98 33 30
----------------

TAS5825_PPC3_Example_Before Rework.cfg

TAS5825_PPC3_LJ_Reworked.cfg

Would you please advise the correct location to write 0x33 commands. Nice to have PPC3 update to support data format option officially.

Thank you and Best regards,

Wayne Chen
10/16/2018

over 5 years ago

0 Shawn Zheng over 5 years ago

TI__Mastermind 24835 points

Hi Wayne,
We are looking into this question and will get back to you later.
Best regards,
Shawn Zheng

0 Andy Liu (BMS) over 5 years ago

TI__Guru 52115 points

Hi Wayne,

I think it would make more sense to place the two extra commands before the line "w 98 03 03".

Andy

0 Wayne Chen (ex FAE) over 5 years ago in reply to Andy Liu (BMS)

Guru 15950 points

Hello Andy.

Thanks a lot. We checked that Location #1 does not work. We will check Location #2 following your recommendations and get you back soon.

Wayne Chen
10/17/2018

0 Wayne Chen (ex FAE) over 5 years ago in reply to Wayne Chen (ex FAE)

Guru 15950 points

Hi Andy,

Your suggestion works. However, I found that we need to write CFG before turning on LJ signal to get correct output signal from TAS5825.

We can get incorrect signal (phase shift or high distortion as the example below) If we turn on LJ signal before sending CFG. Would you pls advise your comment of my investigate?

Thank you and Best regards,

Wayne Chen
10/1/8/2018

0 Andy Liu (BMS) over 5 years ago in reply to Wayne Chen (ex FAE)

TI__Guru 52115 points

Hi Wayne,

I have done some quick testing. However, I cannot see the same issue as you reported.

Basically, I can see the same waveforms even if I turn on signals before initializing TAS5825M devices via i2c. Could you double check?

Andy

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TAS5825M: Question of TAS5825 Audio Format Support in PPC3