SysClock to 216MHz on STM32F7 using PLL not working

[RCres.1]

Hi,

I am trying to set SysClock to 216MHz using stm32f769xx.h

I have no access to MCO pins, so for testing I am trying to blink a led every second. ARR and PSC values to achieve it will confirm if I am to desired SysClock frecuency (Blink led using timer is working with Sysclock to 16MHz using HSI)

This is what I have:

// Configuring main internal regulator output voltage
RCC->APB1ENR |= RCC_APB1ENR_PWREN;
PWR->CR1 |= 0x03<<PWR_CR1_VOS_Pos;
 
//-- Configuring main oscillator
 
	// HSI On
	RCC->CR |= RCC_CR_HSION;
	while (!(RCC->CR & RCC_CR_HSIRDY)) {};
 
	// HSI Calibration Trimming value
	RCC->CR |= 0x10<<RCC_CR_HSITRIM_Pos;
 
// -- Configuring PLL
 
	//PLL Off
	RCC->CR &= ~RCC_CR_PLLON;
 
	// HSI as PLL source
	RCC->PLLCFGR &= ~(0x01<<RCC_PLLCFGR_PLLSRC_Pos);
 
	// Configure PLL M, N, P,Q for 216 MHz
	RCC->PLLCFGR |= 8<<RCC_PLLCFGR_PLLM_Pos;
	RCC->PLLCFGR |= 216<<RCC_PLLCFGR_PLLN_Pos;
	RCC->PLLCFGR |= 2<<RCC_PLLCFGR_PLLP_Pos;
	RCC->PLLCFGR |= 2<<RCC_PLLCFGR_PLLQ_Pos;
 
	//PLL On
	RCC->CR |= RCC_CR_PLLON;
 
	// Enable Over-Drive Mode
	PWR->CR1 |= PWR_CR1_ODEN;
	while (!(PWR->CSR1 & PWR_CSR1_ODRDY)) {};
 
	PWR->CR1 |= PWR_CR1_ODSWEN;
	while (!(PWR->CSR1 & PWR_CSR1_ODSWRDY)) {};
 
	// Set Flash latency
	FLASH->ACR |= 7<<FLASH_ACR_LATENCY_Pos;
	while (!(RCC->CR & RCC_CR_PLLRDY)) {};
 
// -- Configuring Clock
 
	// Select the PLL as the system clock source.
	RCC->CFGR |= (RCC_CFGR_SW_PLL);
	while (!(RCC->CFGR & RCC_CFGR_SWS_PLL)) {};
 
	// Configure Clock preescalers
	RCC->CFGR |= RCC_CFGR_HPRE_0;
	RCC->CFGR |= RCC_CFGR_PPRE1_2;
	RCC->CFGR |= RCC_CFGR_PPRE2_1;
 

For testing, I am using TIM6 with ARR = 63999 and PSC=3374.

However, I think I have not successfully configured SysClock because of blinking led period is not 1s.

Any idea of what I am missing?

Kind Regards,

Rafa