Diff: ST_F401_84MHZ.cpp

Revision:

2:e5c1060ec62d

Parent:

1:d19543ab3afa

Child:

3:1d8106fcb4c5

diff -r d19543ab3afa -r e5c1060ec62d ST_F401_84MHZ.cpp
--- a/ST_F401_84MHZ.cpp	Wed Mar 05 19:53:14 2014 +0000
+++ b/ST_F401_84MHZ.cpp	Wed Mar 05 22:19:14 2014 +0000
@@ -25,4 +25,33 @@
   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
   HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);
 
-}
\ No newline at end of file
+}
+
+
+// use a external 8 MHz crystal to generate the CPU clock
+// You have to add X3 8MHz 
+// C33,C34 18pF 0603
+// R35,R37 0R 0603 or use wire
+void SystemClock_Config_84MHz_external(void)
+{
+  RCC_ClkInitTypeDef RCC_ClkInitStruct;
+  RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
+  RCC_OscInitTypeDef RCC_OscInitStruct;
+
+  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_HSE;
+  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
+  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
+  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
+  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
+  RCC_OscInitStruct.PLL.PLLM = 8;
+  RCC_OscInitStruct.PLL.PLLN = 336;
+  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
+  RCC_OscInitStruct.PLL.PLLQ = 4;
+  HAL_RCC_OscConfig(&RCC_OscInitStruct);
+
+  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1;
+  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
+  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
+  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);
+
+}