STM32L151RC6, I'm not clear what TIMx_IN1, TIMx_IN2, TIMx_IN3 and TIMx_IN3 alternate functions 14 (CPRI) are

[john6518]

Working on a STM32L151RC6, I'm not clear what TIMx_IN1, TIMx_IN2, TIMx_IN3 and TIMx_IN3 are (datasheet, alternate function 14, CPRI).

Belongs to Analog Comparators or Timers?

As far as I figured out, if I select AFIO14, the GPIO pad will be connected to TIMx input capture, whatever is that signal connected to, right?

If so, this is the BUFFERED version of that signal?

Ie. I cannot alter the trigger, just to watch it?

Can I use this signal to have OUT of analog comparators out of package?

I see that COMP1_OUT and COMP2_OUT are not available, instead, can I configure comparator to be the trigger for timer input capture and not use the timer? Just use as COMP_OUT?

Thanks for clarifications,

[waclawek.jan]

Read 8.3.2 Input capture routing subchapter in RM0038.

JW

[waclawek.jan]

I am not an expert on the 'L1 routing fabric, but the input capture routing does not appear to be based on analog switches, rather, these are logic interconnections (multiplexers).

It appears that COMP1 has no other use than to throw and EXTI interrupt, and COMP2 can throw interrupt and be additional input to selected timer. In other words, the comparatos probably can't be output to a pin.

JW

[john6518]

Hmmm... complicated 🙂

But thanks for pin-point, I think it's worth to be mention that in TIMx chapters too..

So if I understood right, more clearly:

• normally, TIM IC is done via CH1,2,3,4 pins, whatever they are on package for particular TIMx
• only for TIM2, TIM3 or TIM4 (only one can be altered)
• all IN1,2,3,4 together, can be moved to other pins from table 42
• by selecting AFIO14

With COMP probably you are right, it is just another MUX entry of TIM IC, connected only internally.

I wish that at least block diagrams to be more accurate in reference manual...