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CC2564C: Buffer overrun messages when trying to setup a phone call

Part Number: CC2564C
Other Parts Discussed in Thread: CC2564MODA

Hi,

I'm struggling for some time now to get telephony working reliably on the CC2564C controller.

We're using A3DP and Assisted HFP in our setup.
We're using Linux as OS with some Bluez extensions to send out the required vendor commands on changing the modes.

Recently we updated our hardware from CC2564B(CC2564MODA) to CC2564C hardware (BDE-BD2564CA).

Our problem is, that we've a stable operation using CC2564B hardware but run into trouble using the CC2564C controller.

These issues happen mainly in situations, when we have A3DP running and we're switching over to assisted HFP.

The phenomens we see are related to audio output.

Looking to the logs, we see a correlation to error messages about buffer overrun messages like this:
DFC TX buffer overrun. requested: 39 available: 180    

Such a situation can be found e.g. in the attached logger file in packet number 81764.
In this particular case, the call was establised, but we only have audio from the connected phone to to our unit, but not in the other way around.

There are further calls in the log.

During the first 5 calls, there was no A3DP stream running.
After the 6th call, we enabled A3DP streaming when no call was active.

The issue does not happen everytime in this constelation but only sometimes.

Can you idenify a reason for the issue and countermeasures we can implement?

Is there a more detailed information available about the changes made between cc2564B and cc2564C hardware?

The cc2564C datasheet mentions in chapter 6.8 some differences.
Are there also updated vendor specific commands available, which address changes in the CC2564C firmware?
Are there any enhanced documents available to interpret the firmware messages beside the HCI commands to explain e.g. the DCF TX Buffer messages and so on more in detail?

IU_APP-768kHz.zip 

 

Best regards,

Adalbert

  • Could it be, that there's an issue due to changes around the PLC and PCM interface mentioned in the datasheet?

    Is there documentation available about the changes in the VS commands?
    I guess there must be a change because of this statement:

    Option added to start and stop the PCM clock as master on the PCM bus even when voice call is not
    active or set a timer to extend the clock after voice or audio is removed

    Attached the firmware, we're using.
    BT-LE is disabled in our configuration.

    8880.TIInit_6.12.26.bts.zip

    Best regards,

    Adalbert

  • expect some delays on our response, since our team is currently in Embedded World