LP-EM-CC2340R5: Why is the TIME524M register of the rtc cleared after a reset by watchdog on the CC2340.

james zhou

Part Number: LP-EM-CC2340R5
Other Parts Discussed in Thread: CC2340R5

Tool/software:

Hi, TI:

Currently the RTC (real time clock) function is being developed in CC2340. I found that on CC2340, when the program is reset by WATCHDOG, the TIME524M register of RTC will be cleared to zero, but in the same case, the TIME524M register will not be cleared to zero on CC2745, so can I set it so that the TIME524M register on CC2340 will not be cleared to zero.

have a good day!

james

2024.09.21

11 months ago

0 Isaac Larson 11 months ago

TI__Expert 5895 points

Hello James,

Please reframe from discussing the CC27xx device on E2E as it is still pre-RTM.

Have you attempted writing 0h to the RST Field of the CTL Register? Please look into section 12.5.2 CTL Register in the Technical Reference Manual for more information.

Thanks,

Isaac

0 james zhou 11 months ago in reply to Isaac Larson

Intellectual 315 points

Hi, Isaac:

Thank you for your response. In CC2340, when I write 0 to register RST, the TIME524M register can count normally, but after triggering the watchdog reset, the TIME524M register will be cleared. When I write 1 to register RST, the TIME524M register will remain in reset state, and its value will always be 0.

have a good day!

james

2024.09.24

0 Isaac Larson 11 months ago in reply to james zhou

TI__Expert 5895 points

Hello James,

I hope you are doing well. I apologize the delay.

I will get back to you tomorrow (09/26) with a response to your last question.

I appreciate your patience.

Thanks,

Isaac

+1 Isaac Larson 11 months ago in reply to Isaac Larson

TI__Expert 5895 points

Hello James,

Correction on my last response. The RTC CTL Register will allow you to reset the timer, not maintain the timer count during a reset. The watchdog timer erases all registers besides for the SRAM, and REG3V3 registers, so the count will be lost on a watchdog timeout/reset.

For more information, please see Section 8.1 - Device Boot and Programming in the CC2340R5 Technical Reference manual.

Thanks,

Isaac

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LP-EM-CC2340R5: Why is the TIME524M register of the rtc cleared after a reset by watchdog on the CC2340.