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authorChris Mason <c.mason@inchipdesign.com.au>2019-09-25 21:38:27 +1000
committerDamien George <damien.p.george@gmail.com>2019-09-26 17:34:04 +1000
commiteb12fa38624a6bb4b71ef72f2aadc0f7ca8f27d1 (patch)
tree75032761ce641b907a9d37937ed9553dacff6d1f
parentf16e4be3fa16a3532bb93ccf88e867d27fe2ff20 (diff)
stm32/powerctrlboot: Add support for HSI at 8MHz on F0 MCUs.
For use with F0 MCUs that don't have HSI48. Select the clock source explicitly in mpconfigboard.h. On the NUCLEO_F091RC board use HSE bypass when HSE is chosen because the NUCLEO clock source is STLINK not a crystal.
-rw-r--r--ports/stm32/boards/NUCLEO_F091RC/mpconfigboard.h10
-rw-r--r--ports/stm32/powerctrlboot.c14
2 files changed, 21 insertions, 3 deletions
diff --git a/ports/stm32/boards/NUCLEO_F091RC/mpconfigboard.h b/ports/stm32/boards/NUCLEO_F091RC/mpconfigboard.h
index e1802da2d..366822d0d 100644
--- a/ports/stm32/boards/NUCLEO_F091RC/mpconfigboard.h
+++ b/ports/stm32/boards/NUCLEO_F091RC/mpconfigboard.h
@@ -16,8 +16,14 @@
#define MICROPY_HW_ENABLE_TIMER (1)
#define MICROPY_HW_HAS_SWITCH (1)
-// For system clock, board uses internal 48MHz, HSI48
-#define MICROPY_HW_CLK_USE_HSI48 (1)
+// For system clock, enable one source:
+//#define MICROPY_HW_CLK_USE_HSI (1) // internal 8MHz -> PLL = 48MHz.
+#define MICROPY_HW_CLK_USE_HSI48 (1) // internal 48MHz.
+//#define MICROPY_HW_CLK_USE_HSE (1) // external crystal -> PLL = 48MHz.
+// For HSE set the crystal / clock input frequency HSE_VALUE in stm32f0xx_hal_conf.h
+#if MICROPY_HW_CLK_USE_HSE
+#define MICROPY_HW_CLK_USE_BYPASS (1) // HSE comes from STLINK 8MHz, not crystal.
+#endif
// The board has an external 32kHz crystal
#define MICROPY_HW_RTC_USE_LSE (1)
diff --git a/ports/stm32/powerctrlboot.c b/ports/stm32/powerctrlboot.c
index 0579853ee..766c52dfb 100644
--- a/ports/stm32/powerctrlboot.c
+++ b/ports/stm32/powerctrlboot.c
@@ -48,7 +48,7 @@ void SystemClock_Config(void) {
RCC->CFGR = 0 << RCC_CFGR_PLLMUL_Pos | 3 << RCC_CFGR_PLLSRC_Pos; // PLL mult by 2, src = HSI48/PREDIV
RCC->CFGR2 = 1; // Input clock divided by 2
- #else
+ #elif MICROPY_HW_CLK_USE_HSE
// Use HSE and the PLL to get a 48MHz SYSCLK
#if MICROPY_HW_CLK_USE_BYPASS
@@ -61,6 +61,18 @@ void SystemClock_Config(void) {
RCC->CFGR = ((48000000 / HSE_VALUE) - 2) << RCC_CFGR_PLLMUL_Pos | 2 << RCC_CFGR_PLLSRC_Pos;
RCC->CFGR2 = 0; // Input clock not divided
+ #elif MICROPY_HW_CLK_USE_HSI
+ // Use the 8MHz internal oscillator and the PLL to get a 48MHz SYSCLK
+
+ RCC->CR |= RCC_CR_HSION;
+ while ((RCC->CR & RCC_CR_HSIRDY) == 0) {
+ // Wait for HSI to be ready
+ }
+ RCC->CFGR = 4 << RCC_CFGR_PLLMUL_Pos | 1 << RCC_CFGR_PLLSRC_Pos; // PLL mult by 6, src = HSI
+ RCC->CFGR2 = 0; // Input clock not divided
+
+ #else
+ #error System clock not specified
#endif
RCC->CR |= RCC_CR_PLLON; // Turn PLL on