PCM4222 BCLK at 48 KHz sample rate to fast

Christopher K.

Other Parts Discussed in Thread: PCM4222, DIR9001

Dear TI Team,

I'm currently building a small audio mixer based on an I2S capable DSP. The audio mixer integrates different IC that are all delivering digital audio via I2C bus in 48 KHz sampel rate qualitiy. So far this setup works well for me. Unfortunately I also want to integrate an audio codec PCM4222 for XLR Inputs and can't get it work. From my point of view the BCLK is to fast.

Example

DIR9001

MCLK 12,288 MHz
BCLK 3,072 MHz
LRCLK 48kHz

works

PCM2707C

MCLK 12,288 MHz
BCLK 3,072 MHz
LRCLK 48kHz

works

PCM4222

MCLK 12,288 MHz
BCLK 6,144 MHz
LRCLK 48 khz

no sound at all.

I have copied most of the EVM reference design.

PCMEN = High

HPFDR, HPFDL = LOW

FS0, FS1 = LOW

DF = LOW

FMT0 = HIGH

FMT1 = LOW

OWL0, OWL1 = LOW

S / !M = LOW

Maybe you can see where the problem is located to generate a higher BCLK

yours faithfully,

Christopher

over 9 years ago

0 Christopher K. over 9 years ago

Intellectual 450 points

Ok after a good night of sleep I found a solution.

The datasheet states that the BCLK is fixed to 128fs during normal operation. This is double the frequency most other TI IC are normaly using. Switching over to double mode will reduce the BCLK to 64fs. Which is compatible to other I2S IC. Therefore to get the right sample rate the clock than must also but divided by 2.

Double Mode PCM4222

LRCLK = fs = 48 kHz

BCLK = 64 x fs = 3,072 MHz

MCLK = 128 x fs = 6,144 MHz

Other IC like DIR9001 or PCM2707C

LRCLK = fs = 48 kHz

BCLK = 64 x fs = 3,072 MHz

MCLK = 256 x fs = 12,288 MHz

best regards,

Christopher

0 Justin Bohr over 9 years ago in reply to Christopher K.

TI__Mastermind 27850 points

Hi Christopher,

I am glad you found a solution and appreciate that you posted it.

Justin

Audio

Audio forum

PCM4222 BCLK at 48 KHz sample rate to fast