stm32timer
I am using an STM32 board (F7 series), and am looking through the HAL API documentation. When I initialize a timer, I see two values, Prescaler and ClockDivision. Now I understand that the Prescaler is used to divide the frequency of the clock. However, what is the ClockDivision supposed to do? I see it has three possible values, DIV1, DIV2, and DIV4.
My auto-generated code says the following.
If you just set the period register to 1, this won't automatically enable interrupt generation. You will need to do 2 additional steps:
Of course, you should not forget to enable clocking of your timer peripheral using the APB1PeriphClockCmd().
There's a detailed example on configuring timers on STM32F4-Discovery here: http://visualgdb.com/tutorials/arm/stm32/timers/
STM32VL-Discovery is a bit different, however the main steps are the same.
You have two problems. The first is that the MCU runs at 168MHz if it has been set up that way, and your compiler may not do that by default. Setting up the clock is a bit arcane. ST provides an excel-based tool to help you create a setup file, and then the file needs to be put in the correct place and some other files need to be edited.
I recommend this site as a place to get all the relevant info. There is an ST page with instructions, but it isn't as clear as some of the other tutorials.
If you do this, the APB1 bus, the one that TIM2 is on, will run at 42MHz max, giving you an 84MHz TIM2 clock (it's doubled by PLL). If you need faster than that, you must use one of the timers on APB2, which goes twice as fast. Note that that bus doesn't have any 32-bit timers.
The second issue is, as you said, you exceeded a maximum value. Yes, you need to play with the two values. If you divide your clock by (42000-1) with the prescalar to give you a 2 kHz time base, and then set the period to (2000-1), there's your 1 second interval.
Of course, you must TURN ON THE CLOCK to the TIM2 peripheral, and then enable TIM2, or nothing will work.
Best Answer
With a big assumption that everything below holds true or at least be similar to F7 series description. I could be completely wrong! Please double check!
According to the stm32 F4 family datasheet register description, the "ClockDivision" stands for
I could not find any specific documentation related to F7 series and I am not quite aware of dead-time generators usage but ETR stands for "External Trigger Input".
Beware TIM1 is a special Timer, the same description do not hold true for other general pupose timers(ex. TIM2 etc.)
Also, HAL API Documentation is particularly not useful as it is just an accumulation of all the HAL Library comments without any description. If you are still interested, this might be helpful for you.