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| author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2012-02-11 08:57:22 +0000 |
|---|---|---|
| committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2012-02-11 08:57:22 +0000 |
| commit | 267cd61c1914bc1d71f47f020d391c2d3ac1c224 (patch) | |
| tree | 070a8a95f0b45ef4154afc21314f6d14b8a5ae73 /os/hal/src | |
| parent | 0921f80daa58844fc056ac6720720682da9ceb45 (diff) | |
| download | ChibiOS-267cd61c1914bc1d71f47f020d391c2d3ac1c224.tar.gz ChibiOS-267cd61c1914bc1d71f47f020d391c2d3ac1c224.tar.bz2 ChibiOS-267cd61c1914bc1d71f47f020d391c2d3ac1c224.zip | |
Fixed bug 3485500.
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@3950 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/hal/src')
| -rw-r--r-- | os/hal/src/hal.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/os/hal/src/hal.c b/os/hal/src/hal.c index 3cf15226a..dad579ad0 100644 --- a/os/hal/src/hal.c +++ b/os/hal/src/hal.c @@ -120,4 +120,75 @@ void halInit(void) { boardInit();
}
+#if HAL_IMPLEMENTS_COUNTERS || defined(__DOXYGEN__)
+/**
+ * @brief Realtime window test.
+ * @details This function verifies if the current realtime counter value
+ * lies within the specified range or not. The test takes care
+ * of the realtime counter wrapping to zero on overflow.
+ * @note When start==end then the function returns always true because the
+ * whole time range is specified.
+ * @note This is an optional service that could not be implemented in
+ * all HAL implementations.
+ * @note This function can be called from any context.
+ *
+ * @par Example 1
+ * Example of a guarded loop using the realtime counter. The loop implements
+ * a timeout after one second.
+ * @code
+ * halrtcnt_t start = halGetCounterValue();
+ * halrtcnt_t timeout = start + S2RTT(1);
+ * while (my_condition) {
+ * if (!halIsCounterWithin(start, timeout)
+ * return TIMEOUT;
+ * // Do something.
+ * }
+ * // Continue.
+ * @endcode
+ *
+ * @par Example 2
+ * Example of a loop that lasts exactly 50 microseconds.
+ * @code
+ * halrtcnt_t start = halGetCounterValue();
+ * halrtcnt_t timeout = start + US2RTT(50);
+ * while (halIsCounterWithin(start, timeout)) {
+ * // Do something.
+ * }
+ * // Continue.
+ * @endcode
+ *
+ * @param[in] start the start of the time window (inclusive)
+ * @param[in] end the end of the time window (non inclusive)
+ * @retval TRUE current time within the specified time window.
+ * @retval FALSE current time not within the specified time window.
+ *
+ * @special
+ */
+bool_t halIsCounterWithin(halrtcnt_t start, halrtcnt_t end) {
+ halrtcnt_t now = halGetCounterValue();
+
+ return end > start ? (now >= start) && (now < end) :
+ (now >= start) || (now < end);
+}
+
+/**
+ * @brief Polled delay.
+ * @note The real delays is always few cycles in excess of the specified
+ * value.
+ * @note This is an optional service that could not be implemented in
+ * all HAL implementations.
+ * @note This function can be called from any context.
+ *
+ * @param[in] ticks number of ticks
+ *
+ * @special
+ */
+void halPolledDelay(halrtcnt_t ticks) {
+ halrtcnt_t start = halGetCounterValue();
+ halrtcnt_t timeout = start + (ticks);
+ while (halIsCounterWithin(start, timeout))
+ ;
+}
+#endif /* HAL_IMPLEMENTS_COUNTERS */
+
/** @} */
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