CC2564C: Does CC2564C support RF frequency calibration?

Nick Sun

Intellectual 2265 points

Part Number: CC2564C
Other Parts Discussed in Thread: CC2564

Hi team,

Here's a request from customer:

As the title says, does CC2564C support RF frequency calibration?

Can you help for checking this point?

Thanks and Regards,

Nick

over 1 year ago

0 Jonathan Cohen over 1 year ago

TI__Intellectual 1600 points

Hi Nick,

I am not exactly sure what you mean by RF frequency calibration. Can you give me a better idea what the customer is looking to calibrate?

Thanks,

Jonathan

0 Xinjian Xiong over 1 year ago

TI__Prodigy 120 points

Bluetooth is the need to calibrate the frequency, because the crystal oscillator, the difference in the parasitic capacitance of the Bluetooth chip, the tolerance of the crystal load capacitance and other factors, will lead to frequency offset inconsistency, Bluetooth association stipulates that the Bluetooth frequency offset within ± 75KHZ, if the frequency deviates more from the 2.4G center, it will lead to unstable Bluetooth connection, so the frequency needs to be corrected.

+1 Jonathan Cohen over 1 year ago in reply to Xinjian Xiong

TI__Intellectual 1600 points

Thank you for the clarification.

The CC2564 does support this type of RF calibration by sending a HCI command: HCI_VS_DRPb_Enable_RF_Calibration.

The full list of HCI commands for the CC2564 is written in detail in the file I have attached here.

3187.CC256x_VS_HCI_Commands.pdf

Best Regards,

Jonathan

0 Xinjian Xiong over 1 year ago in reply to Jonathan Cohen

TI__Prodigy 120 points

thank you Jonathan , it helps a lot!

0 Xinjian Xiong over 1 year ago in reply to Jonathan Cohen

TI__Prodigy 120 points

Jonathan , Could you also advise how to make HCI_VS_DRPB_ENABLE_RF_Calibration happen? Because the chip is going out to the market, the Bluetooth frequency will always be offset due to temperature, etc., so what method is used to calibrate this frequency offset, how to make it? Thank you

0 Jonathan Cohen over 1 year ago in reply to Xinjian Xiong

TI__Intellectual 1600 points

Hello,

Let me check with our expert on the issue, I will get back to you in the next couple of days.

Thanks for your patience,

Jonathan

+1 Jonathan Cohen over 1 year ago in reply to Jonathan Cohen

TI__Intellectual 1600 points

I did some checking, and the best way to apply the HCI_VS_DRPB_ENABLE_RF_Calibration command is through HCITester. HCITester allows you to send specific HCI commands to the bluetooth stack, or create automatic scripts which send many commands at once.

For the RF calibration, you can either send the HCI command manually after boot, or you can add it to the BTS file. The BTS file is the firmware initialization script which can be modified to also send the HCI RF calibration command. This makes things easier because it's completely automatic, and you can easily share it with customers. You can also create any general script with the desired commands and run that script any time. I have attached a user's guide for the HCITester tool which goes in depth on how to modify the BTS file, create scripts, or just send single HCI commands.

Hope this helps.

Best regards,

Jonathan

HCITester.pdf

Bluetooth®︎

Bluetooth forum

CC2564C: Does CC2564C support RF frequency calibration?