Interconnecting TDM lines

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mga2009

Member
Joined 2015
#1
I am looking to use an XMOS board (MiniDSP MCHStreamer or DIYHK Multichannel XMOS) to output 16 channels from my PC using TDM16 protocol. From there I will use E-APO for 5x 2way active system.

Now, TDM16 only requires one cable for interconnecting, right? So on my XMOS board I will only have 1 cable (plus other 3 for clock) for connecting to a DAC, DSP or CODEC.

My question is, what happens If wanted to connect the TDM line to a DAC board like the chipdip.ru PCM5142 (PCM5142 audio DAC с miniDSP, Преобразователь: I2S - Аудио. 2 линейных выхода = 2В RMS, 384kHz/32bit, DirectPath™, Электронные войска | купить в розницу и оптом) where I only have one pin for TDM input? how do I connect the other 15 DACS? Is it possible?

I know this is a very basic question, but still can't solve it.

I also have a side project using 2x AD1938 CODEC in "daisy chain mode" paired with an ADAU1452 for getting an 8x16 ADC/DAC DSP, but I am running some issues with SPI and the CODECS, so maybe USB is a whole easier alternative.

Cheers.
 
#2
You'll probably need a buffer that will mirror the 4 lines to max 8 DACs (16 channels gives you 8 stereo pairs) and you'll have to make sure you can program the DACs to select the channels for each one if the DAC even supports more than 2 channels in the TDM stream. I did not find such registers in the pcm5142 datasheet and their TDM graphs show only 2 channels.
 
#4
wealas said:
You'll probably need a buffer that will mirror the 4 lines to max 8 DACs (16 channels gives you 8 stereo pairs) and you'll have to make sure you can program the DACs to select the channels for each one if the DAC even supports more than 2 channels in the TDM stream. I did not find such registers in the pcm5142 datasheet and their TDM graphs show only 2 channels.
Click to expand...

rfbrw said:
You have to create a TDM daisy chain using the DIN and DOUT pins of the dacs.
Click to expand...

Thanks for your replies!

And, how do I make a TDM daisy chain connection?

Use the DIN for input and the DOUT for output and use PurePath Studio to choose TDM - Daisy Chain - and select the correct channel?
 
#5
At TDM16 rates the PCM5142 will only support up to16/96. LRCLK is common to all dacs.

tdm.jpg
 
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