CC1310: ROM Bootloader

Danilo A.

Part Number: CC1310

Hi Team,

Posting on behalf of our customer.

I designed a custom PCB based on the CC1310 reference design. In my board, I did not route the JTAG programming interface, because I intended to program the device through the UART ROM bootloader.

I am using the CC1310 in the 7×7 package and connected the UART bootloader pins through DIO2 and DIO3. I power the board with 3.3 V and try to communicate with the device using a Python script over UART, but I do not receive any response from the chip.

At the moment, the board does not acknowledge any bootloader communication attempt, and the result is effectively “No Response.”

Could you please advise what conditions are required for the CC1310 to respond through the UART bootloader on a fresh board, and what hardware or boot configuration points I should verify?

I would also appreciate your help confirming whether the issue could be related to:

- Bootloader entry conditions
- Reset or power sequencing
- UART pin usage on DIO2/DIO3
- Any required hardware connections that may have been missed in the design

Regards,

Danilo

2 months ago

0 Arthur R☑️ 2 months ago

TI__Mastermind 27887 points

Hi Danilo,

I assume that the customer has read https://www.ti.com/lit/an/swra466e/swra466e.pdf

There are several reasons it may not work:

There is already an image flashed on the CC1310, and it did not enable the bootloader backdoor pin
The device's flash is not empty. The empty device will have its serial bootloader enabled when the flash is empty.

Regards,

Arthur

0 Danilo A. 2 months ago in reply to Arthur R☑️

TI__Mastermind 34110 points

Hi Arthur,

Please see our customer's response below.

Thank you for your prompt response.

The CC1310F128RGZ devices we are using were purchased directly from Mouser Electronics, an authorized Texas Instruments distributor, so we are confident the flash memory is empty (factory state) and the ROM bootloader should be enabled by default.

Current measurements (CC1310 powered with 3.3 V, no UART adapter connected):

Supply current: ~1.7 mA

Voltage at Pin 8 (DIO_3 / bootloader UART TX): < 1 V

Questions:

Is a DIO_3 reading below 1 V normal at idle, or should DIO_3 be actively driven to 3.3 V whenever the ROM bootloader is running?

Does DIO_3 require an external pull-up resistor, or is the chip's internal output driver sufficient?

Could this low DIO_3 voltage be the root cause of the bootloader not responding to our UART sync attempts?

Thank you again for your support.

Regards,

Danilo

0 Arthur R☑️ 2 months ago in reply to Danilo A.

TI__Mastermind 27887 points

Hi Danilo,

This probably means that DIO3 is floating, which is maybe caused by the following: CC1310: CC1310 crash issue - Sub-1 GHz forum - Sub-1 GHz - TI E2E support forums

Regards,

Arthur

0 Danilo A. 2 months ago in reply to Arthur R☑️

TI__Mastermind 34110 points

Hi Arthur,

Thank you for your guidance. The customer updated that the issue has been resolved, and it turned out that the error was related to the hardware.

Regards,

Danilo