Initial commit of library code, moved from leaftest repo

git-svn-id: https://leaflabs.googlecode.com/svn/trunk/library@69 749a229e-a60e-11de-b98f-4500b42dc123

1 files changed, 30 insertions, 0 deletions

diff --git a/src/lib/systick.c b/src/lib/systick.c
new file mode 100644
index 0000000..f328ae0
--- /dev/null
+++ b/src/lib/systick.c
@@ -0,0 +1,30 @@
+#include "systick.h"
+
+#define MILLIS_INC 1
+
+volatile uint32_t systick_timer_overflow_count = 0;
+volatile uint32_t systick_timer_millis = 0;
+static uint8_t systick_timer_fract = 0;
+
+void systick_init(void) {
+    /* Set the reload counter to tick every 1ms  */
+    SYSTICK_RELOAD = MAPLE_RELOAD_VAL;
+
+    /* Clock the system timer with the core clock
+     * and turn it on, interrrupt every 1ms to keep track of millis()*/
+    SYSTICK_CSR = SYSTICK_SRC_HCLK |
+                  SYSTICK_ENABLE   |
+                  SYSTICK_TICKINT;
+}
+
+void SysTickHandler(void)
+{
+   uint32_t m = systick_timer_millis;
+   uint8_t f = systick_timer_fract;
+
+   m += MILLIS_INC;
+   systick_timer_millis = m;
+   systick_timer_overflow_count++;
+}
+
+