-// Install an interrupt handler.
-void installInterrupt(void (*isrPtr)(void), unsigned char offset);
+/** Timer reload value for 29.491 MHz crystal. */
+#define RELOAD_29_491 0xfd99
+
+/** Timer reload value for 36.864 MHz crystal. */
+#define RELOAD_36_864 0xfd00
+
+/** Timer reload value for 58.982 MHz crystal. */
+#define RELOAD_58_982 0xfecc
+
+/** Timer reload value for 73.728 MHz crystal. */
+#define RELOAD_73_728 0xfe80
+
+extern unsigned int task_gettickreload(void);
+
+extern void task_settickreload(unsigned);