Posted on September 12, 2017 at 19:21part of code from CoIDE
//----------Clock configure-------------//
RCC->CFGR |= RCC_CFGR_PLLMULL4; // PLL multiplication factor = 4
RCC->CR |= RCC_CR_PLLON; // PLL start
RCC->CFGR |= RCC_CFGR_SW_PLL; // PLL as SYCLK
RCC->CFGR |= RCC_CFGR_MCO_PLL;
//or sysclk //RCC->CFGR |= RCC_CFGR_MCO_SYSCLK;
RCC->CFGR |= RCC_CFGR_MCO_PRE_16; //mco div 16
HSI=8Mhz
8MHz/2(prediv)*4(pllmull)=16MHz
... but frequency meter show 6Mhz on MCO!!! even when MCO_PRE_16.
6x16=96!!! Is it real sysclk=96MHz?
When MCO_PRE is equal 64 MCO freq is 1.5MHz-->and again sysclk=96MHz
...when i put HSI or HSE to MCO, all work good and MCO out shows real freq
Then i used timer...
//----------TIM14 configure-------------//
TIM14->PSC = 16000;
TIM14->ARR = 1000;
TIM14->CR1 |= TIM_CR1_CEN;
TIM14->DIER |= TIM_DIER_UIE;
NVIC_EnableIRQ(TIM14_IRQn);
... interrupt was calld 6 times per seconds)))
16000x1000=16M clock cycles
16Mx6Hz(interrupt)=96MHz!!!
Is it real, or where my mistake?
