DIX4192: Having issues locking on to audio signal

Jackson Hayward

Part Number: DIX4192
Other Parts Discussed in Thread: TM4C123GH6PM

Hi!

I'm looking to use the DIX4192 to do audio equalization and MUXing for a startup project. I purchased a couple for testing but I can't seem to get the chip to lock on to the digital audio signal I am sending it. I've reviewed the document a few times and I've run out of ideas on what I could be doing wrong. It could be possible that I accidentally damaged the chip while playing with it but I would like to see if anyone could spot flaws in my setup.

For the digital audio input I followed this image found in the DIX4192 document:

I'm using the optical receiver found here https://www.digikey.com/product-detail/en/everlight-electronics-co-ltd/PLR135-T/1080-1431-ND/2693959.

Here is an image of the output going directly into RX1+. RX1- is grounded with the series capacitor like in the doc image:

I'm using this 24.576MHz oscillator https://www.digikey.com/product-detail/en/abracon-llc/ASTX-H11-24.576MHZ-T/535-12038-1-ND/3906609

Here is the image of my oscillator output when connected to the DIX4192:

Using Code Composer Studio v7 I am able to read and write to the registers using the I2C interface. When I connect the oscillator output to the RCKLI pin and set the registers 0x0D-0x11 it shows that I have successfully written to the registers but the Lock pin does not go low.
On the otherhand, if I connect the oscillator to the MCLK pin and try to read the registers they all return a value of 0xFF as if there is some kind of error.

Any help of suggestions would be greatly appreciated!

over 7 years ago

0 Steve-Wilson over 7 years ago

TI__Mastermind 30210 points

Hi Jackson,
Are you able to share a schematic? You could just cut the DIX4192 portion.
We will take a look and get back to you on Monday.

Best regards,
-Steve Wilson

0 Jackson Hayward over 7 years ago in reply to Steve-Wilson

Prodigy 105 points

Could you elaborate on "just cut the DIX4192 portion"? Working on getting you a schematic now.

0 Steve-Wilson over 7 years ago in reply to Jackson Hayward

TI__Mastermind 30210 points

Hi Jackson,
Yeah, that was a little vague. Sorry.

All I meant was if you didn’t want to share a whole schematic, You could send a screenshot of just the portion of the schematic using the DIX4192. I’ve also sent a connection request to you, so you can share it with me off forum.

-Steve Wilson

0 Steve-Wilson over 7 years ago in reply to Steve-Wilson

TI__Mastermind 30210 points

Hi Jackson,
just a quick question, You are using your own PCB for this right? not our EVM? And you are interfacing to some host processor, I am assuming a MSP430/2?

best regards,
-Steve Wilson

0 Steve-Wilson over 7 years ago in reply to Steve-Wilson

TI__Mastermind 30210 points

Jackson,
Sorry, I see the schematic you sent. So yes, you are using your own board with a host processor, which processor is it?\

when you say you are able to write to the registers, you are getting some kind of ACK?
but you are also unable to read back the values to write?
-Steve

0 Jackson Hayward over 7 years ago in reply to Steve-Wilson

Prodigy 105 points

I'm using the TM4C123GH6PM as the host processor.

When I have the oscillator output connected to the RXCKI pin I can write values to the registers and then read those values back without a problem, however the LOCK pin does not activate and go low to signal a lock condition nor do the registers indicate that a lock condition has occurred.

When I have the oscillator output connected to the MCLK pin and I try to read the registers with the same code that works with RXCKI the function always returns the value 255 as if all the registers were set to all high bits.

0 Steve-Wilson over 7 years ago in reply to Jackson Hayward

TI__Mastermind 30210 points

Hello Jackson,

Understood, perhaps it would help if you provide your register settings?
I imagine you are changing the master clock select bits in register 4 when you use RXCKI, you are changing them back to the default state when using MCLK?

best regards,
-Steve Wilson

0 Jackson Hayward over 7 years ago in reply to Steve-Wilson

Prodigy 105 points

Sure,

I don't actually set register 4 because I am not using serial audio.

I currently set registers 0xD - 0x11

0xD it set to either 0 or 8 depending on if I am using RXCKI or MCLK.

0xE is 0 or 1 depending on if I want RXCKO

0xF - 0x11 are set to 34, 0, and 0 because my oscillator is running at 24.5760 MHz

0 Justin Dougherty over 7 years ago in reply to Jackson Hayward

Prodigy 30 points

Any update on this topic?

0 Steve-Wilson over 7 years ago in reply to Justin Dougherty

TI__Mastermind 30210 points

Justin and Jackson,

I've ordered an EVM so that I can reproduce the problem and troubleshoot on my end too. However, this will likely not arrive until monday morning. I apologise for the delay there, but i will do everything I can to help you get this working.

Out of curiosity what happens if you have clocks connected to both RXCKI and MCLK?

best regards,

-Steve Wilson

0 Jackson Hayward over 7 years ago in reply to Steve-Wilson

Prodigy 105 points

When both RXCKI and MCLK are connected all registers return the value 255. This is the case regardless of if I set register 0xD to either 0 or 8.

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DIX4192: Having issues locking on to audio signal