TIMER (Duty and OCActive)

[esiqueira]

Posted on July 11, 2012 at 15:46

Hi,

I would like to know why in TIM_OCMode_PWM1, I can calculate the frequency 'Duty cicle'                         TIM_CLK / (TIM_Period + 1)                36MHz/(999+1)  Frequencia  =  --------------------------------    Logo, ------------------ = 18KHz                                 (TIM_Prescaler + 1)                               (1+1) (see attached file) And in TIM_OCMode_Timing the period was set with 65535???? 'OCActive' (see attached file) #stm32-duty-cicle-ocactive-pulse

[Tesla DeLorean]

Posted on July 12, 2012 at 20:32

Because presumably using the maximal 16-bit counter value makes advancing the CCR at each CC interrupt profoundly easier to do, and doesn't require any modulo math using slow divide instructions. And issues with CC/Update interrupts.

By advancing the CCR you can generate a far wider range of frequencies than you can with the integer divider methods.

[esiqueira]

Posted on July 13, 2012 at 20:04

THANKS clive1