PCM1840: Format support (TDM4/TDM8)

Roy Chou1

Part Number: PCM1840

Hi Team,

Based on the format pins description in section 7.3.2, it only supports outputting TDM 4 with 32-bit slot width.

But table 3 of section 7.3.3 shows that it supports BCLK / FSYNC = 256. It is a conflict with what mentioned in section 7.3.2 that the codec only supports TDM4 with 32-bit slot width.

Based on the document, it is more likely that the codec does not support TDM8.

May you help comment it? Thank you.

Regards,

Roy

over 3 years ago

0 Jeff McPherson over 3 years ago

TI__Mastermind 39885 points

Hi Roy,

You're correct that the device does not support TDM8 in that it will not output 8 channels of data, only 4. However TDM8 clocking is still valid since the device will simply leave slots 5-8 empty.

Best regards,

Jeff

0 Roy Chou1 over 3 years ago in reply to Jeff McPherson

TI__Genius 15015 points

Hi Jeff,

Do you mean PCM1840 can still output 8-slot TDM but the valid data can only be put in the first 4 slots? Since the audio amplifier we want to connect to PCM1840 currently receives 8-slot TDM, with either the first 4 or last 4 slots filled in with valid data.

Regards.

Roy

0 Roy Chou1 over 3 years ago in reply to Roy Chou1

TI__Genius 15015 points

Hi Jeff,

Any comments?

Roy

0 Brian Donoghue over 3 years ago in reply to Roy Chou1

TI__Intellectual 2620 points

Roy,

Sorry for the delay, Jeff has been out of office the past week and will be returning tomorrow. But I agree that the first 4 slots will be valid data and the remaining 4 will be empty.

Brian

Audio

Audio forum

PCM1840: Format support (TDM4/TDM8)