difference between real measured frequency and set frequency

 if ((RCC->CR & RCC_CR_HSERDY) != 0) {
 printf("HSE is enabled and ready.\n");
 } else {
 printf("HSE is not enabled or ready.\n");
 }

 printf("System Clock: %lu Hz\n", HAL_RCC_GetSysClockFreq());
 printf("APB1 Timer Clock: %lu Hz\n", HAL_RCC_GetPCLK1Freq());
 printf("APB2 Timer Clock: %lu Hz\n", HAL_RCC_GetPCLK2Freq());


 uint32_t apb1_prescaler = (RCC->D2CFGR & RCC_D2CFGR_D2PPRE1) >> RCC_D2CFGR_D2PPRE1_Pos;
 uint32_t apb2_prescaler = (RCC->D2CFGR & RCC_D2CFGR_D2PPRE2) >> RCC_D2CFGR_D2PPRE2_Pos;

 printf("APB1 Prescaler: %lu\n", apb1_prescaler);
 printf("APB2 Prescaler: %lu\n", apb2_prescaler);

 uint32_t pclk1 = HAL_RCC_GetPCLK1Freq(); // Get APB1 clock
 uint32_t pclk2 = HAL_RCC_GetPCLK2Freq(); // Get APB2 clock

 printf("APB1 Clock: %lu Hz\n", pclk1);
 printf("APB2 Clock: %lu Hz\n", pclk2);

 // If prescaler > 1, Timer Clock = PCLK * 2
 if (apb1_prescaler > 3) { // Values >3 mean prescaler is applied
 printf("APB1 Timer Clock: %lu Hz\n", pclk1 * 2);
 } else {
 printf("APB1 Timer Clock: %lu Hz\n", pclk1);
 }

 if (apb2_prescaler > 3) {
 printf("APB2 Timer Clock: %lu Hz\n", pclk2 * 2);
 } else {
 printf("APB2 Timer Clock: %lu Hz\n", pclk2);
 }