TLV320AIC3106: Write to registers at runtime

Hi,

In the datasheet section 10.3.2 onwards talks about how to generate the audio interface from clock to the different audio format.

https://www.ti.com/lit/ds/symlink/tlv320aic3106.pdf?ts=1632170828749&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTLV320AIC3106

It's good to understand how the clocks are generated and there's also an excel sheet that calculate the clock and setting for you below.

Once you understand that, you can read or write the respective register setting using the register map in section 10:6.

This is standard I2C interface and if you want there are examples as well on how the IC is configured in the following user guide:

https://www.ti.com/lit/ug/slau855/slau855.pdf?ts=1632171100734&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTLV320AIC3106

Regards.

Hello,

Thanks for the answer. The excel is really useful.

I already read the clock generation part, I understand I have to slghtly modify the PLL values (J,D,P, R) in order to change the sampling rate. My issue comes with the I2C communicaton with the codec. The I2C is already initialized and opened in the function I2CCodecIfInit:

void I2CCodecIfInit(unsigned int baseAddr, unsigned int intCh,
unsigned int slaveAddr)
{
I2C_Params i2cParams;
I2C_HwAttrs mcasp_i2c_cfg;
I2C_slaveAddr =(uint32_t)slaveAddr;
I2C_init();

I2C_Params_init(&i2cParams);
i2cParams.transferMode = I2C_MODE_BLOCKING;

I2C_socGetInitCfg(I2C_MCASP_INSTANCE, &mcasp_i2c_cfg);

/* Modify the default I2C configurations if necessary */
mcasp_i2c_cfg.enableIntr=false;
/* Set the default I2C init configurations */
I2C_socSetInitCfg(I2C_MCASP_INSTANCE, &mcasp_i2c_cfg);
I2C_handle_glob = I2C_open(I2C_MCASP_INSTANCE, &i2cParams);
}

Once the I2C communication is opened I understand I can use the I2C functions to send and read data from the registers. Here is what I can't undersand, can I call these I2C functions from the USB callback? The idea is on each callback, read the actual value of J,D,P,R and slightly change the sampling rate value, then writting these registers again.

I see that, reading the register 102, for instance, I get the reset value from it (0x02) instead of the written value (0x08), so supposedly I can't read the actual values for J,D,R,P... This is what I don't get. 

Thanks for your tme

jp

Hi,

As there are several pages of register, you would want to specify which page the transactions are for.

I have attached an example of the transaction when writing a value 5 to "J" in register 6 of page 0.

You can probe your I2C lines and check the transaction like the attached.

I2C Example.pptx

Regards.

Hi,

As there are several pages of register for this device, you would want to specify the page # follows by the register itself.

I have attached an example of the transaction when writing a value 5 to J below.

0257.I2C Example.pptx

Give a try and probe the I2C lines to ensure the format and transactions are correct.

Regards.

Hello,

Thanks again for the answer. I tried selecting the page right before reading the register but still the read value is not correct.

By the way, in my codec (aic3106) register 6 is for the D value , not J.

I think the issue may be somewhere else.

Kind regards,

jp

Hi,

Change the register accordingly as what I have provided is an example of the I2C transaction.

You want to see the I2C signals with a scope/analyzer like Saleae and ensure the format is correct and device ACK the transaction like what I have provided above. From there then you can tell if the transaction is successful or not.

Regards.

Hello,

Thanks for your answer. I tried to read the signal but i can't see anything in the oscilloscope. I'm using the same function to write/read in the registers as provided in the example (CodecRegWrite or CodecRegRead) which uses the I2C library to do the transactions. I still think the problem is where I am calling these functions, the I2C transactions should be correct.

Regards,

jp

Hi,

I'm not familiar with the TMS320C6748 part, but from the AIC3106 side those are the I2C transactions and if the command is configured correctly you should see the I2C traces in the scope. Let me assign this to Jianzhong Xu from TMS320C6748 who helped you initially with this part.

Regards.

Hello Jpom,

In case you're not aware of, there are I2C example projects in OMAP-L138 PDK. You may want to look at those examples for I2C programming on C6748 DSP. 

Regards,

Jianzhong

Hello,

Thanks once more. I read the examples and I still can't understand the difference with my code.

Let's say we want to read register 102 from the AIC3106.

With the I2C initializated and opened with handler I2C_handle_glob and working in master mode, we do:

unsigned char writebuf[1];
I2C_Transaction i2cTransaction;

regAddr = AIC31_P0_REG102 ; // we want to read register 102 (for example)

slaveData[0] = regAddr;

// Here we have to send an I2C message with the address of the i2c slave as 'Address' field and the register address as data

writebuf[0]=slaveData[0]; 

// We initialize the transaction with default values
I2C_transactionInit(&i2cTransaction);

// 1. First we setup the I2C message to send

// Override the default address with our slave address
i2cTransaction.slaveAddress = I2C_slaveAddr;

// Write the register address to the slave
i2cTransaction.writeBuf = (uint8_t *)&writebuf[0];

// Number of bytes to write
i2cTransaction.writeCount = 1;

// Read buffer to store the answer from the slave
i2cTransaction.readBuf = (uint8_t *)&slaveData[0];

// Read one byte from the slave
i2cTransaction.readCount = 1; 

// 2. Send the I2C message
I2C_transfer(I2C_handle_glob, &i2cTransaction);

Sorry but this is made this way in all the code and also in the examples. I need more details on what should I do with the i2c transaction. I still think there is a problem setting this inside the USB callback (I can't use the I2C functions directly at this point because the handler is declared in the codec_if.c file, so I use the CodecRegWrite and Read functions)

Regards,

jp

Hi jp,

Thanks for the update. I'll close this thread.

Regards,

Jianzhong