TDM8 verification at Output in ADAU1452
Dear Team
Would like to know the feasibility of verifying TDM8 at the output in ADAU1452 RevBZ board ...
Is it possible to verify this or is there a limitation on the output just like we do have a limitation at the input side ?
Please let me know and if it is possible update me with the process of verification too
Audio Signal Processors
adau1452
Dave
SigmaDSP Audio Processors
Hello Annihilate_123,
The limitations only apply to the codec when the codec is operating in standalone mode. So you have two choices.
If you MUST use the codec, on other words you are not planning on sending and receiving the TDM data to and from another board. So for those conditions...
1) You need to use the codec on the evaluation board.
For this case you must modify the evaluation board and the USBi for external control of the codec. Then you can change the codec to accept and send TDM8 signals.
2) If you are interfacing with an external board and do not need to use the on-board codec.
For this case I will split it up to the serial output of the DSP and the serial input of the DSP.
The codec DAC inputs are setup as a slave so you can setup the clocks and data into any format or sampling rate you like and jumper the clocks and SDATA out to an external board. The codec on the eval board will not know what to do with these signals and will not output anything but it will not matter since you are not using it and it will not change the signals. Yes, the termination and capacitance is still there but jumper wires are terrible as well for a transmission line. So for the DSP serial output ports, you can use any of them and set them up as you wish.
For the DSP serial input ports. The problem here is that the SDATA output of the codec is always driving so you cannot drive a second signal into the serial ports. There are four serial ports and the codec ADC uses only the first two. SDATA_IN_O and 1. SDATA_IN ports 2 and 3 are not used and appear on header on the PCB. So use either of these ports to jump over to an external PCB. If you really need to use serial port 0 or 1 because you want to use TDM-16, then you can remove the series resistor on the ADC output port of the codec. Then you can gain back the first two serial input ports.
By the way, you can use a scope to look at the serial data. That helps.
I did put together a test program recently where I jumpered the serial output port back into the serial input port on the eval board. Then I can test the TDM-8 channel assignments. If you like I can locate the program.
Dave T
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