diff options
| author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2012-01-04 14:29:02 +0000 |
|---|---|---|
| committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2012-01-04 14:29:02 +0000 |
| commit | c498fdc4d64f1de8706f9d3b224dc244c5e91dc2 (patch) | |
| tree | 0c96b48c552f7df4179910711fb3d37eeea3a2aa /os/hal/include | |
| parent | 8bd4ec7b8474fcfce5c4441131f841175d62e0b0 (diff) | |
| download | ChibiOS-c498fdc4d64f1de8706f9d3b224dc244c5e91dc2.tar.gz ChibiOS-c498fdc4d64f1de8706f9d3b224dc244c5e91dc2.tar.bz2 ChibiOS-c498fdc4d64f1de8706f9d3b224dc244c5e91dc2.zip | |
Added time conversions to RT counter code. Documentation improvements.
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@3728 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/hal/include')
| -rw-r--r-- | os/hal/include/hal.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/os/hal/include/hal.h b/os/hal/include/hal.h index ceb047db1..b7e6141cc 100644 --- a/os/hal/include/hal.h +++ b/os/hal/include/hal.h @@ -73,6 +73,52 @@ /*===========================================================================*/
/**
+ * @name Time conversion utilities for the realtime counter
+ * @{
+ */
+/**
+ * @brief Seconds to realtime ticks.
+ * @details Converts from seconds to realtime ticks number.
+ * @note The result is rounded upward to the next tick boundary.
+ *
+ * @param[in] sec number of seconds
+ * @return The number of ticks.
+ *
+ * @api
+ */
+#define S2RTT(sec) (halGetCounterFrequency() * (sec))
+
+/**
+ * @brief Milliseconds to realtime ticks.
+ * @details Converts from milliseconds to realtime ticks number.
+ * @note The result is rounded upward to the next tick boundary.
+ *
+ * @param[in] msec number of milliseconds
+ * @return The number of ticks.
+ *
+ * @api
+ */
+#define MS2RTT(msec) (((halGetCounterFrequency() + 999UL) / 1000UL) * (msec))
+
+/**
+ * @brief Microseconds to realtime ticks.
+ * @details Converts from microseconds to realtime ticks number.
+ * @note The result is rounded upward to the next tick boundary.
+ *
+ * @param[in] usec number of microseconds
+ * @return The number of ticks.
+ *
+ * @api
+ */
+#define US2RTT(usec) (((halGetCounterFrequency() + 999999UL) / 1000000UL) * \
+ (usec))
+/** @} */
+
+/**
+ * @name Macro Functions
+ * @{
+ */
+/**
* @brief Returns the current value of the system free running counter.
* @note This is an optional service that could not be implemented in
* all HAL implementations.
@@ -95,6 +141,53 @@ */
#define halGetCounterFrequency() hal_lld_get_counter_frequency()
+/**
+ * @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.
+ *
+ * @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.
+ *
+ * @api
+ */
+#define halIsCounterWithin(start, end) \
+ (end > start ? (halGetCounterValue() >= start) && \
+ (halGetCounterValue() < end) : \
+ (halGetCounterValue() >= start) || \
+ (halGetCounterValue() < end))
+/** @} */
+
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
|