PCM1864evm 4 Channel TDM Mode shows one channel over USB

Aaron Jones

Other Parts Discussed in Thread: PCM1864EVM, PCM1864

TI,

I have a setup where the PCM1864evm has 4 channel microphone in. When I set up the EVM with the included USB-I2X cable to connect to the computer, I see one device.

The PCM1864 is sending data in TDM mode, 64-bit, 16bit-per-channel, over four channels.

How can I view each channel individually on the computer? Do I need to hook it up some other way than the USB-I2X adapter board?

Regards,

Aaron Jones

over 8 years ago

0 Justin Bohr over 8 years ago

TI__Mastermind 27880 points

Hi Aaron,

If your aim is to test TDM mode, then you will need to use another device to interface to the PC, as the TAS1020B on the USB-I2X board can only handle I2S with 2 channels. If your aim is to look at each channel individually you can change which channels go to the TAS1020B by changing the mixer settings and leaving the PCM1864 in I2S mode.

If you want to focus on getting all 4 channels at the same time you will have to use an Audio Precision, or a device like one from MiniDSP: www.minidsp.com/.../usbstreamer

This doesn't have the software support for TDM, but can handle multiple I2S data lines, and therefore up to 8 channels of audio over I2S to the PC over USB.

Justin

0 Diego Melendez over 8 years ago

TI__Guru 57800 points

Hi, Aaron,

My colleague has been notified about your questions and will help you as soon as possible.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Aaron Jones over 8 years ago in reply to Justin Bohr

TI__Intellectual 760 points

Justin,

Thanks for your quick response.

Doesn't the PCM1864 support only one I2S data line as dout? Would your multiple I2S suggestion require a different device?

Regards,

Aaron

0 Justin Bohr over 8 years ago in reply to Aaron Jones

TI__Mastermind 27880 points

Hi Aaron,

The PCM1864 can use a GPIO as a second DOUT for I2S therefore being able to output 4 channels over I2S without TDM.

Justin

Audio

Audio forum

PCM1864evm 4 Channel TDM Mode shows one channel over USB