Add Systick initialization

main.c

@@ -39,10 +39,6 @@ void GPIO_PORT_B_init(void)
 
 }
 
-
-
-
-
 void UART1_WRITE(char data)
 {
     while (UART1_FR_R & 0x20);       // Wait until TX FIFO is not full
@@ -55,6 +51,20 @@ char UART1_READ(void)
     return (char)UART1_DR_R;         // Return received data
 }
 
+#define STCTRL *((volatile uint32_t *) 0xE000E010)          // control and status
+#define STRELOAD *((volatile uint32_t *) 0xE000E014)        // reload value
+#define STCURRENT *((volatile uint32_t *) 0xE000E018)       // current value
+
+#define CLOCK_HZ 16000000       // CLOCK FREQUENCY OF EK-TM4C123GXL
+#define SYSTICK_RELOAD_VALUE(us) ((CLOCK_HZ / 1000000) * (us) - 1)  // SYSTICK RELOAD VALUE
+
+void systick_setting(void)                      // SYSTICK SETUP FUNCTION
+{
+    STRELOAD = SYSTICK_RELOAD_VALUE(1000);     // RELOAD VALUE FOR 1ms
+    STCTRL |= (1 << 0) | (1 << 2);              // Enable SysTick with system clock
+    STCURRENT = 0;                               // Clear current value
+}
+
 
 
 void GPIOF_interruptHandler(void)               // Interrupt handler for GPIO Port F
@@ -85,7 +95,8 @@ void GPIOF_interruptHandler(void)               // Interrupt handler for GPIO Po
 int main(void)                                 // MAIN FUNCTION
 {
     GPIO_PORT_F_init();                        // GPIO INITIALISATION FUNCTION
-
+    GPIO_PORT_B_init();
+    systick_setting();                         // SYSTICK SETUP
     while (1)
     {
     }