diff --git a/bsp/tm4c129x/applications/board.c b/bsp/tm4c129x/applications/board.c
index 6c64a8c141b4b15b6d47761057316601dc54b576..0da547e8674d942548080d2c76c6e798c02892e1 100644
--- a/bsp/tm4c129x/applications/board.c
+++ b/bsp/tm4c129x/applications/board.c
@@ -25,8 +25,7 @@
 #include "driverlib/rom_map.h"
 
 #define SYS_CLOCK_DEFAULT 120000000
-uint32_t SysClock;
-
+uint32_t SystemCoreClock;
 #define FAULT_NMI               2           // NMI fault
 #define FAULT_HARD              3           // Hard fault
 #define FAULT_MPU               4           // MPU fault
@@ -81,12 +80,12 @@ int rt_hw_cpu_init(void)
     // Set the clocking to run directly from the external crystal/oscillator.
     // TODO: The SYSCTL_XTAL_ value must be changed to match the value of the
     // crystal on your board.
-    SysClock = MAP_SysCtlClockFreqSet(
+    SystemCoreClock = MAP_SysCtlClockFreqSet(
                 (SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480),
                 SYS_CLOCK_DEFAULT);
 
     MAP_SysTickDisable();
-    MAP_SysTickPeriodSet(SysClock/ RT_TICK_PER_SECOND - 1);
+    MAP_SysTickPeriodSet(SystemCoreClock/ RT_TICK_PER_SECOND - 1);
     MAP_SysTickIntEnable();
     MAP_SysTickEnable();	
 
diff --git a/bsp/tm4c129x/applications/board.h b/bsp/tm4c129x/applications/board.h
index 8c1b6141722e27b407148514d8ed4468b2dab87b..8103d0b1f198bd148c5cffc44e69f31e6b3e48f2 100644
--- a/bsp/tm4c129x/applications/board.h
+++ b/bsp/tm4c129x/applications/board.h
@@ -22,8 +22,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-extern uint32_t SysClock;
-
+extern uint32_t SystemCoreClock;
 #ifdef __CC_ARM
 extern int Image$$RW_IRAM$$ZI$$Limit;
 #define HEAP_BEGIN  ((void *)&Image$$RW_IRAM$$ZI$$Limit)
diff --git a/bsp/tm4c129x/drivers/drv_uart.c b/bsp/tm4c129x/drivers/drv_uart.c
index 7b8153d4c60821245e4906c93d4f288622b47f4d..ef95144af15667055cc6661c0652ebaac9d0d07b 100644
--- a/bsp/tm4c129x/drivers/drv_uart.c
+++ b/bsp/tm4c129x/drivers/drv_uart.c
@@ -92,7 +92,7 @@ static rt_err_t hw_configure(struct rt_serial_device *serial, struct serial_conf
 	}
 	
 	// Initialize UART0 peripheral with given to corresponding parameter
-    MAP_UARTConfigSetExpClk(uart->hw_base, SysClock, cfg->baud_rate, config);
+    MAP_UARTConfigSetExpClk(uart->hw_base, SystemCoreClock, cfg->baud_rate, config);
 	MAP_UARTFIFOEnable(uart->hw_base);
 
 	// Enable the UART.