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Associate III
May 31, 2024
Question

STM32WLE5JCI6TR Sub-GHz RTC and STM32 RTC

  • May 31, 2024
  • 1 reply
  • 708 views

From RM0461, Reference manual, STM32WLEx advanced Arm®-based 32-bit MCUs
with sub-GHz radio solution

Is it correct that there are TWO RTCs inside STM32WLE5JCI6TR

a) one is the normal STM32 RTC and just call RTC in many ST application notes

b) the other is a seperate "Sub-GHz radio RTC" on third party "silicon"

Many thanks

----

a) STM32 RTC is section 30 of the Reference Manual, Real-time clock (RTC)

b) The OTHER is section 4.10.51 to 4.10.54

 

4.10.51 Sub-GHz radio RTC control register (SUBGHZ_RTCCTLR)
Address offset: 0x902
Reset value: 0x00

4.10.52 Sub-GHz radio RTC period MSB register (SUBGHZ_RTCPRDR2)
Address offset: 0x906
Reset value: 0x00

4.10.53 Sub-GHz radio RTC period mid-byte register
(SUBGHZ_RTCPRDR1)
Address offset: 0x907
Reset value: 0x00

4.10.54 Sub-GHz radio RTC period LSB register (SUBGHZ_RTCPRDR0)
Address offset: 0x908
Reset value: 0x00

1 reply

STTwo-32
Technical Moderator
June 28, 2024

Hello @David_ 

The STM32WL include one RTC module. But when employing the Sub-GHz module, the RTC is used as a dedicated RTC for the Sub-GHz module to ensure that his HW timers keep running even in low power modes. More details are available on the AN5406.

Best Regards.

STTwo-32

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