+ /* Every time the counter counts down to zero
+ * a systick exception is invoked. Systick has
+ * exception number 15. in the vector table */
+ ivt_set_gate(15, systick_handler, 0);
+
+ /* Get calibration and set this to 1 sec
+ * !Most boards have a 1 ms or 10 ms
+ * calibration value */
+ int calib = (*STK_CALIB << 0) * 500;
+
+ /* The counter reload registers counts down to zero
+ * and then it is restores the value */
+ rwrite(STK_RELOAD, calib);
+