TAS2562: I am using TAS2562 with CC8530, but it will not send acknowledge bit when addressed on i2c bus

Austin Petty

Part Number: TAS2562
Other Parts Discussed in Thread: CC8530, , , TAS2563

Hello,

One of our new products has a custom PCB using 2 TAS2562s and a CC8530. The chip gets stuck in a startup loop because the i2c bus is not working. I have included a scope capture depicting the TAS2562 not acknowledging when addressed on the i2c bus. The address select pin is tied to VDD, so its i2c address should be 4F. I measured the voltage on The enable pin as 3.2V (IOVDD is 3.3V), so it should not be in hardware shutdown. The i2c bus uses 4.7kOhm pull up resistors and has 33 ohm series termination resistors on the CC8530 side of the bus. I am unsure of how to proceed to find the source of the problem–any recommendations to continue problem solving would be greatly appreciated.

Thank you,

Austin

7 months ago

+1 Arthur Brown 7 months ago

TI__Mastermind 18305 points

Hi Austin,

looks like the customer is only sending the 7-bit address 0x4f to attempt communication with the device,

to open communication with the device the host will need to send the 7-bit address + the read/write bit. 0 = write, 1 = read.

send address 0x9f for a read operation, and 0x9e for a write

regards,

Arthur

0 Austin Petty 7 months ago in reply to Arthur Brown

Prodigy 110 points

Hi Arthur,
There are 9 clock pulses. 7 for the address, 1 for r/w, and 1 for acknowledge. The 8th bit was high to signify it is a read operation. I think the first 8 bits are correct. The TAS2563 should be pulling the last bit low, but is not. I included another screenshot showing the r/w bit asserted low to signify a write operation, but TAS2563 still does not acknowledge.

Thank you,

Austin

0 Austin Petty 7 months ago in reply to Arthur Brown

Prodigy 110 points

Hi Arthur,

Sorry, I understand what you are saying now, and it fixed my problem. I found the paragraph in the tas2563 data sheet explaining why it is 0x9F instead of 0x4F and it helped clear things up. Thank you again for your help,

Austin

0 Arthur Brown 7 months ago in reply to Austin Petty

TI__Mastermind 18305 points

good to hear Austin,

I will close the thread

Regards

Audio

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TAS2562: I am using TAS2562 with CC8530, but it will not send acknowledge bit when addressed on i2c bus