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CCS/TIDA-00489: Is backdoor access necessary?

Part Number: TIDA-00489
Other Parts Discussed in Thread: CC1310

Tool/software: Code Composer Studio

Hey guys,

we have the TIDA-00489 design, though we have removed some stuff including J3, which was somehow related to the backdoor mode? As a starting point for software development we used the sensor software from 15.4 Stack. I recently stumbled over the backdoor pre-defined symbols and SET_CCFG_BL_CONFIG_BL_ENABLE=0xC5 was enbaled. I changed it to 0x00 to disable it. So, far I havent noticed any issues.

So my question is, if this could potentially lead to any strange behavior during flashing of the sensors in the production line?

best wishes


  • Hello Slev1n,  While we have received your query and forwarded it to our Building Automation Systems team, we have determined that it will be necessary to consult with our SimpleLlink product team on your firmware oriented answer.  As is such, we are currently routing your question to that team.  Please allow us an another business day to respond to your question in detail. 

    Best Regards,

    John Fullilove

    Reference Design Operations

    Texas Instruments

  • The main purpose of the CC13x2/CC26x2 ROM bootloader is to support functionality for programming a flash image into the device flash over either SPI or UART.

    The built-in bootloader start running after a power-on reset if there is no valid application image in flash

    Alternatively, the bootloader start if the so-called bootloader backdoor is enabled and the associated pin that opens the backdoor is set to the correct logic level.

    Disabling the bootloader backdoor will remove the possibility to force entry of the ROM boot loader even if a valid image is present in flash

    See for more details.


  • Hey Siri,

    thank you for the elaborate response. I am familiar with the functionality of the bootloader used. Using an XDS debug probe still allows me to enter the ROM bootloader even without backdoor. So, flashing the device is not a problem when an XDS debug probe is applied. However, regarding OAD, usually the new image is stored in external flash and transferred via SPI (at least in the case of CC1310 chips) to the ROM bootloader.

    Do you know how entry into the ROM bootloader is possible when already a valid image is present in case of OAD? I cant imagine that a hardware interface to the backdoor pin is necessary here.

    best wishes


  • hey TER,

    thank you for the link I once read it but this was a long time ago. Since we use the CC1310 we will have to use the OFF-Chip OAD.

    best wishes