TI AIC23 audio codec

HuskyEngineer

I have this Altera AD/DA Data Conversion Daughter Card that uses a TI AIC23 Audio Codec to interface with the audio jacks (line in/out, mic in, headphone)

The daughter card plugs into an Altera FPGA that runs a NIOS II software processor so I'm pretty much coding in C. The problem is there doesn't seem to be any support material for this codec on this daughter card so it looks like I'm going to have to code the library that controls this from scratch.

I guess my first question is whether or not I can treat the SPI control as just 3 individual I/O pins and bit bang the control and data signals to the AIC23 chip and control it that way. If I do that and am able to set the control registers, how do I send it a signal say to the headphones so I can hear a signal?

over 10 years ago

0 Converter Apps over 10 years ago

TI__Mastermind 28585 points

0 HuskyEngineer over 10 years ago in reply to Converter Apps

Prodigy 100 points

I got that from the datasheet but I wasn't sure if I can bit bang the SPI signals or does it have to be a specific clock for this to work? Also, what do you mean by analog I/O? Isn't the I2S sent as a 16 bit digital signal that represents the analog? It's sent through the DIN pin right?

0 Converter Apps over 10 years ago in reply to HuskyEngineer

TI__Mastermind 28585 points

SPI can be bit banged.

I2S is sent via Din and Dout (and LRCK and MCLK).

The analog would be to the mic inputs.

0 HuskyEngineer over 10 years ago in reply to Converter Apps

Prodigy 100 points

I've tried bit banging and I can't seem to get any response. Does it require a specific clock frequency to work for it's SPI line? Also, I've been trying to test whether or not the configuration works by turning no the bypass and sidetone modes to see if I can get the line out to play something I put into the mic and line in.

Any help would be appreciated!

0 HuskyEngineer over 10 years ago in reply to Converter Apps

Prodigy 100 points

I've gotten the SPI to work with bit banging and now I'm trying to get the I2S data to be sent back to me. For that, can the BCLK signal be generated with bit banging as well if I run the AIC23 in slave mode? Or does it need to be more precise?

0 Converter Apps over 10 years ago in reply to HuskyEngineer

TI__Mastermind 28585 points

BCLK doesn't need to be precise. It just needs to get all of the bits before the next frame. MCLK and LRCK should be precise...

0 HuskyEngineer over 10 years ago in reply to Converter Apps

Prodigy 100 points

Ok, looks like I didn't have the MCLK at 12Mhz. It appears to work well now although I am getting a decent amount of noise.

If anyone else is working with a NIOS II with an AD/DA daughter card I am posting my libraries here:

https://github.com/atching/niosii-aic23

Audio

Audio forum

TI AIC23 audio codec