2013-06-10 02:19 PM
i used timer2 and it's clock source from APB1 and Prescaler value for APB1 is 4
it's mean's APB1 work at 42mhz ''168mhz/4 '' becuase the maximum frequency is 42mhz for APB1. i searched in internet and some people write the timer2 clocked at 84mhz not 42mhz and it's true. but i cant find in this stm32f4 datasheet2013-06-10 03:18 PM
Yes, review the clock tree in the Reference Manual. For DIV2 on the APB it is DIV1 on the TIMCLK, for DIV4 on APB it is DIV2 on the TIMCLK