diff --git a/main.c b/main.c
index 1e97729..a8db78f 100644
--- a/main.c
+++ b/main.c
@@ -2,6 +2,9 @@
 #include <stdbool.h>
 #include "tm4c123gh6pm.h"
 
+void Systick_Handler(void);
+void systickInit(void);
+
 int main(void)
 {
     SYSCTL_RCGC2_R |= 0x00000020;       /* enable clock to GPIOF */
@@ -26,4 +29,22 @@ int main(void)
 
 }
 
-void Syst
+void systickInit()
+{
+    NVIC_ST_CURRENT_R = 0;
+    NVIC_ST_CTRL_R = 0x07;
+    NVIC_ST_RELOAD_R = 8000000;
+}
+
+void Systick_Handler()
+{
+    systickInit();
+       if (GPIO_PORTF_DATA_R & 0x04) {
+           GPIO_PORTF_DATA_R &= ~0x04;
+
+       }
+       else {
+           GPIO_PORTF_DATA_R |= 0x04;
+       }
+       systickInit();
+    }