diff --git a/stm/system_stm32f4xx.c b/stm/system_stm32f4xx.c
index 8568a9b4f1039e13333eb8f347d2ff0e04d1ce7c..12ac4d6b565a5d21adc511a0036bd793b1c8a945 100644
--- a/stm/system_stm32f4xx.c
+++ b/stm/system_stm32f4xx.c
@@ -54,9 +54,9 @@
   *-----------------------------------------------------------------------------
   *        APB2 Prescaler                         | 2
   *-----------------------------------------------------------------------------
-  *        HSE Frequency(Hz)                      | 8000000     changed dpgeorge
+  *        HSE Frequency(Hz)                      | HSE_VALUE 
   *-----------------------------------------------------------------------------
-  *        PLL_M                                  | 8           changed dpgeorge
+  *        PLL_M                                  | (HSE_VALUE/1000000)
   *-----------------------------------------------------------------------------
   *        PLL_N                                  | 336
   *-----------------------------------------------------------------------------
@@ -251,7 +251,7 @@
 
 /************************* PLL Parameters *************************************/
 /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N */
-#define PLL_M      8
+#define PLL_M      (HSE_VALUE/1000000)
 /* USB OTG FS, SDIO and RNG Clock =  PLL_VCO / PLLQ */
 #define PLL_Q      7