1 files changed, 72 insertions, 0 deletions
diff --git a/core/time.c b/core/time.c
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index 0000000..164d978
--- /dev/null
+++ b/core/time.c
@@ -0,0 +1,72 @@
+/* *****************************************************************************
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Created: 12/18/09 02:41:36
+ *  Copyright (c) 2009 Perry L. Hung. All rights reserved.
+ *
+ * ****************************************************************************/
+
+/**
+ *  @file time.c
+ *
+ *  @brief 
+ */
+
+#include "libmaple.h"
+#include "systick.h"
+#include "time.h"
+
+#define CYCLES_PER_MICROSECOND  72
+#define FUDGE                   42
+
+extern volatile uint32_t systick_timer_millis;
+
+unsigned long millis() {
+   unsigned long m;
+   m = systick_timer_millis;
+   return m;
+}
+
+void delay(unsigned long ms)
+{
+   unsigned long start = millis();
+
+   while (millis() - start <= ms)
+      ;
+}
+
+
+
+#if 1
+void delayMicroseconds(uint32_t us) {
+    uint32_t target;
+    uint32_t last, cur, count;
+    /* fudge factor hacky hack hack for function overhead  */
+    target = us * CYCLES_PER_MICROSECOND - FUDGE;
+
+    /* Get current count */
+    last = systick_get_count();
+    cur = systick_get_count();
+    count = last;
+    while ((count-cur) <= target) {
+        cur = systick_get_count();
+
+        /* check for overflow  */
+        if (cur > last) {
+            count += MAPLE_RELOAD_VAL;
+        }
+        last = cur;
+    }
+}
+#endif