TDM between AD1401 and AD1940 eval boards revisited
Hello,
Sorry I had marked my previous post http://ez.analog.com/message/117014#117014
as assumed answered by mistake, but I would appreciate help with this.
I've been able to send I2S stereo audio from a AD1401 eval board to a AD1940d board by connecting them as described in
http://ez.analog.com/thread/35830
Now I'd like to try sending TDM audio across the same interface, but cannot make it work. As far as I can tell, the wiring between the boards as well as the boards' jumper settings remain the same for I2S and TDM. After setting both chips' register controls for TDM, I find that the -1401 board is not sending any data to the -1940 board.
I attached the project file for each board:
1401 -- Two channels of analog in, straight to two used channels (out of eight) TDM
1940 -- TDM in, two channels out to analog
I'm hoping someone could look at the register settings therein and see what's wrong.
Bob
Hi Bob,
Please see this thread. It looks like a typo in SigmaStudio.
http://ez.analog.com/message/122988#122988
The register settings for "TDM" in the ADAU1401 register window don't match the datasheet. We're going to fix this in the next update.
Thanks!
Brett
Hello Brett,
That was it! Setting the output serial to TDM like this:
but setting MP6 to straight serial I2S:
did the trick. The capture window shows how "TDM" mode here sets incorrect lower bits ("Reserved" in the data sheet):
So our mixer project over here is beginning to perk. Thanks so much!
Bob
BTW -- in addition to the register changes above, I had to rewire my jumpers between boards compared to the non-multiplexed I2S case. The AD1940 accepts TDM data at its SData_3 and SData_2 inputs (not SData_0 and 1 as I had assumed.
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