STM32L1 TIM10/11 trigger selection, reference manual is inconsistent

[ondrudav]

Hi, I'm trying to measure the frequency of multiple signals using the STM32L1515RC. Using the External clock mode 1, I need one timer per signal. My question is if TIM10 and TIM11 support this mode.

The TIM10 and TIM11 block diagrams (Figure 131, Figure 132) in the reference manual RM0038 shows them as having the capability, but 40 pages later the "TIM10/11 slave mode control register 1" has the relevant bits marked as reserved.

So I'm not sure if i can use TIM10/11 to measure external signal frequency.

[Imen.D]

Hello @David Ondrušek​ 

Only TIM9 have the capability to be clocked from external clock source mode 1.

TIM10/11 doesn’t support External clock mode 1 but External clock mode 2 only. And there is no possibility to assign TIMx_ETR signal AF to GPIO.

I think these timers cannot be clocked by external signal.

Let me check back with the IP Owner and I will come back to you with details.

Imen

[Imen.D · Accepted solution]

Hi @David Ondrušek​ ,

The synchronization module of TIM10 is wrong (and misleading) and it should be removed.

The impacted reference manuals will be updated to make this point more clear.

Thanks for pointing out this issue.

Imen