(STM32F105C8, STM32CubeIDE 1.9.0, MacOS 11.6.5) Using STM32CubeIDE, how do I can't get TIM3 to tick/count when TIM2 overflows. (TIM2 does count up)

[FMoto.1]

TIM2:

Clock source: Internal

Master/Slave Mode: Disabled (Trigger input not delayed)

Trigger Event Selection: Update Event

TIM3:

Slave Mode: Trigger Mode

Trigger Source: ITR1

TIM2 counts up like it should, but TIM3 doesn't count the over flow, but has increasing numbers that don't make sense.

What am I doing wrong?

All the example I could find don't use the IDE/MX and I couldn't figure out how to map the registers to the HAL names.

Thanks in advance!

[TDK]

You want external clock mode 1, not trigger mode.

 

See "Using one timer as prescaler for another timer" in the reference manual.

[FMoto.1]

Thank you, THANK YOU!!!

I was thinking external clock on a pin, not external to the timer, but internal to the F105.