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authorPerry Hung <iperry@alum.mit.edu>2010-03-30 22:03:00 -0400
committerPerry Hung <iperry@alum.mit.edu>2010-03-30 22:03:00 -0400
commit2c33d55bae8f9e0e009634072ab05302fc734a65 (patch)
tree63285f96e795fc423cd5bf573340d12f6c8d5513 /core/time.c
parent23149e9706ff0a6a338e13804456dff4c655e34b (diff)
parent1d3861ef93f8423176c6010ab606abdab00a7cbd (diff)
downloadlibrambutan-2c33d55bae8f9e0e009634072ab05302fc734a65.tar.gz
librambutan-2c33d55bae8f9e0e009634072ab05302fc734a65.zip
Merge branch 'master' into rcc-dev
Conflicts: Makefile
Diffstat (limited to 'core/time.c')
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1 files changed, 72 insertions, 0 deletions
diff --git a/core/time.c b/core/time.c
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+/* *****************************************************************************
+ * 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