diff options
| -rw-r--r-- | ports/stm32/powerctrlboot.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/ports/stm32/powerctrlboot.c b/ports/stm32/powerctrlboot.c index e320cc4db..de7c9d88a 100644 --- a/ports/stm32/powerctrlboot.c +++ b/ports/stm32/powerctrlboot.c @@ -82,11 +82,21 @@ void SystemClock_Config(void) { // Enable power control peripheral __HAL_RCC_PWR_CLK_ENABLE(); - // Use the 16MHz internal oscillator + // Set flash latency to 1 because SYSCLK > 16MHz + FLASH->ACR |= FLASH_ACR_LATENCY; + + // Enable the 16MHz internal oscillator RCC->CR |= RCC_CR_HSION; while (!(RCC->CR & RCC_CR_HSIRDY)) { } - const uint32_t sysclk_src = 1; + + // Use HSI16 and the PLL to get a 32MHz SYSCLK + RCC->CFGR = 1 << RCC_CFGR_PLLDIV_Pos | 1 << RCC_CFGR_PLLMUL_Pos; + RCC->CR |= RCC_CR_PLLON; + while (!(RCC->CR & RCC_CR_PLLRDY)) { + // Wait for PLL to lock + } + const uint32_t sysclk_src = 3; // Select SYSCLK source RCC->CFGR |= sysclk_src << RCC_CFGR_SW_Pos; |