diff options
| -rw-r--r-- | ports/stm32/powerctrlboot.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/ports/stm32/powerctrlboot.c b/ports/stm32/powerctrlboot.c index 206b19b75..880e43e04 100644 --- a/ports/stm32/powerctrlboot.c +++ b/ports/stm32/powerctrlboot.c @@ -154,12 +154,23 @@ void SystemClock_Config(void) { #elif defined(STM32WB) +#include "stm32wbxx_ll_hsem.h" + +// This semaphore protected access to the CLK48 configuration. +// CPU1 should hold this semaphore while the USB peripheral is in use. +// See AN5289 and https://github.com/micropython/micropython/issues/6316. +#define CLK48_SEMID (5) + void SystemClock_Config(void) { // Enable the 32MHz external oscillator RCC->CR |= RCC_CR_HSEON; while (!(RCC->CR & RCC_CR_HSERDY)) { } + // Prevent CPU2 from disabling CLK48. + while (LL_HSEM_1StepLock(HSEM, CLK48_SEMID)) { + } + // Use HSE and the PLL to get a 64MHz SYSCLK #define PLLM (HSE_VALUE / 8000000) // VCO input is 8MHz #define PLLN (24) // 24*8MHz = 192MHz |