6.2.3 Start Firmware Download

The download process goes through the following steps:

  1. Send standard Reset command Op Code 0x0c03 to the controller.
  2. Raise the controller baud rate to a higher baud rate to speed up the download process; this step is done by issuing the vendor-specific UART Parameters Command to the controller with the required baud rate. Disable the flow control at this point.
  3. Raise the host baud rate to a matching baud rate.
  4. Start downloading the firmware image to the controller IRAM starting at address 0x80000000 through the Write Memory vendor-specific HCI commands.
  5. Send the vendor-specific reset HCI command to transfer the execution from the Boot ROM code to the downloaded firmware code.
  6. Update the host UART’s baud rate and flow control settings to the initial settings that the firmware operates and communicates with the host UART's settings.
  7. Raise the controller baud rate and flow control settings to the required run time operational settings.
  8. Raising the host UART settings to match the controller settings.
  9. Change the BD Address of the controller if the BD Address is not stored on the Bluetooth controller.
  10. Send the standard HCI Reset command to the controller to operate with the new BD Address.