STM32F4 - Question regarding Timer Unit

[florianaugustin9]

Posted on October 11, 2013 at 12:29

Hello experts,

at home I'm using STM32F4 amongst other MCUs but at university we're learning about Freescale PowerPC architecture. Some of them have a TPU - Timer processing unit, which can help to reduce interrupt load of the RCPU and increase accuracy. I think that for example a frequency measurement can be done and on another pin double or half (or what you want) of the measure frequency can be output without any work of the RCPU or any Interrupt. The TPU is like some small MCU in the MCU... Is there anything like this on the STM32F4, in my case STM43F407? Thank you!!

[Tesla DeLorean]

Posted on October 11, 2013 at 15:00

For high input frequencies you'd use the external source to clock the timer, and then gate the timer over a longer integration period (1sec, 100ms, whatever). If you didn't want to gate it you could sample periodically either with interrupt or DMA, and compute a delta measurement of the count.

The timers in the STM32 are not particularly exciting, they only have one counting element and multiple latches/comparators.