Peter Drescher / ST_401_84MHZ

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Dependents:   Nucleo_spi_master_20MHz Nucleo_vs_Arduino_Speed_Test DMA_I2S_Test MPU9150AHRS ... more

Files at this revision

API Documentation at this revision

Revision 2:e5c1060ec62d, committed 2014-03-05

Comitter:
dreschpe
Date:
Wed Mar 05 22:19:14 2014 +0000
Parent:
1:d19543ab3afa
Child:
3:1d8106fcb4c5
Commit message:
Add external crystal X3 mode

Changed in this revision

ST_F401_84MHZ.cpp Show annotated file Show diff for this revision Revisions of this file
ST_F401_84MHZ.h Show annotated file Show diff for this revision Revisions of this file 
--- 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);
+
+}

--- a/ST_F401_84MHZ.h	Wed Mar 05 19:53:14 2014 +0000
+++ b/ST_F401_84MHZ.h	Wed Mar 05 22:19:14 2014 +0000
@@ -2,5 +2,6 @@
 #define MBED_ST_F401_84MHZ_H
 
 void SystemClock_Config_84MHz_internal(void);
+void SystemClock_Config_84MHz_external(void);
 
 #endif
\ No newline at end of file