ti8148 audio clock

lihou ma

Prodigy 90 points

Hello

i want set AUXOSC_IN clock as audio osc clock. how to modify clock814x_data.c?

over 13 years ago

0 Pavel Botev over 10 years ago in reply to bob lee

TI__Guru**** 170625 points

Bob,

We do not have more dividers for the FS clock on AFSX pin. You can try to control the FS speed with modifying the below bits:

AFSXCTL[15:7] XMOD

AFSXCTL[4] FXWID

Regards,
Pavel

0 bob lee over 10 years ago in reply to Pavel Botev

Genius 3210 points

Hi Pavel,

I have set the XMOD & FWID bits of AFSXCTL,but not succeed.

Would you give me some suggestions ?

Thank you .

Bob

0 Pavel Botev over 10 years ago in reply to bob lee

TI__Guru**** 170625 points

Bob,

I will check this with McASP team, but it will take time.

Regards,
Pavel

0 bob lee over 10 years ago in reply to Pavel Botev

Genius 3210 points

Hi Pavel,

Thank you.

Bob

0 bob lee over 10 years ago in reply to bob lee

Genius 3210 points

Hi Pavel,

I have got the 8kHz clock.

Thank you again.

Bob

0 Pavel Botev over 10 years ago in reply to bob lee

TI__Guru**** 170625 points

Hi Bob,

I am glad to see you are making a progress.

bob lee said:
I have got the 8kHz clock.

Could you please share how you managed to change the frame sync clock from 64KHz to 8KHz? Is it modifying the AFSXCTL register?

Best regards,
Pavel

0 bob lee over 10 years ago in reply to Pavel Botev

Genius 3210 points

Hi Pavel,

I modify the below code in Board-ti8148evm.c.

static struct snd_platform_data ti8148_evm_snd_data = {
.tx_dma_offset = 0x46800000,
.rx_dma_offset = 0x46800000,
.op_mode = DAVINCI_MCASP_IIS_MODE,
.num_serializer = ARRAY_SIZE(ti8148_iis_serializer_direction),
// .tdm_slots = 2,----->old
.tdm_slots = 16,----->new
.serial_dir = ti8148_iis_serializer_direction,
.asp_chan_q = EVENTQ_2,
.version = MCASP_VERSION_2,
.txnumevt = 1,
.rxnumevt = 1,
};

Bob

0 Pavel Botev over 10 years ago in reply to bob lee

TI__Guru**** 170625 points

Bob,

This is the feedback from the McASP team:

In principle, it might be best to work backwards, starting from the frame sync. The point isn’t to start with some high clock and then manipulate it to get the frame sync; it’s the other way around. You figure out what frame sync frequency you need, and configure the other clocks based on that.

So try it this way—start with 8 kHz. Then figure out how many frames you have. Then figure out how many bits per frame. For instance if you have 32 bit data, and two frames, you’re going to end up with

8 kHz x 2 frames x 32 bits = 512 kHz.

That’s your desired bit clock. So you figure out how to divide down the high clock to get that bit clock.

0 bob lee over 10 years ago in reply to bob lee

Genius 3210 points

Hi Pavel,

I have another question to be solved.

I have two boards.So I want one board to send PCM data packets and other one to receive the data packets.

How to do ? Is there any tool?

Do you understand me? If not, please let me know .

Bob

0 Pavel Botev over 10 years ago in reply to bob lee

TI__Guru**** 170625 points

Bob,

bob lee said:
I have another question to be solved.

Can you open new e2e thread for that.

BR
Pavel

0 bob lee over 10 years ago in reply to Pavel Botev

Genius 3210 points

Hi Pavel,

Ok,wait for a few minutes.Thank you.

Bob

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ti8148 audio clock