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			593 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			593 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /** @file */
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| 
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| // xos_timer.h - XOS Timer API interface and data structures.
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| 
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| // Copyright (c) 2003-2015 Cadence Design Systems, Inc.
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| //
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| // Permission is hereby granted, free of charge, to any person obtaining
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| // a copy of this software and associated documentation files (the
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| // "Software"), to deal in the Software without restriction, including
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| // without limitation the rights to use, copy, modify, merge, publish,
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| // distribute, sublicense, and/or sell copies of the Software, and to
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| // permit persons to whom the Software is furnished to do so, subject to
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| // the following conditions:
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| //
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| // The above copyright notice and this permission notice shall be included
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| // in all copies or substantial portions of the Software.
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| //
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| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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| // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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| // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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| // IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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| // CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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| // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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| // SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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| 
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| // NOTE: Do not include this file directly in your application. Including
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| // xos.h will automatically include this file.
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| 
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| 
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| #ifndef __XOS_TIMER_H__
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| #define __XOS_TIMER_H__
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| 
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| #include "xos_types.h"
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| 
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| #ifdef __cplusplus
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| extern "C" {
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| #endif
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| /// Function pointer type for timer callbacks.
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| ///
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| //-----------------------------------------------------------------------------
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| typedef void (XosTimerFunc)(void * arg);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| /// Timer event structure. Used to track pending timer events.
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| ///
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| //-----------------------------------------------------------------------------
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| typedef struct XosTimer {
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|     struct XosTimer *   next;   ///< Pointer to next event in list.
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|     uint64_t            when;   ///< Time (clock cycles) at which to trigger.
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|     uint64_t            delta;  ///< Delta for next re-trigger, 0 if none.
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|     XosTimerFunc *      fn;     ///< Function to call when timer expires.
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|     void *              arg;    ///< Argument to pass to called function.
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|     bool                active; ///< Set if active (in some list of events).
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| #if XOS_OPT_TIMER_WAIT
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|     XosThreadQueue      waitq;  ///< Queue of threads waiting on this timer.
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| #endif
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| #if XOS_TIMER_DEBUG
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|     uint32_t            signature;
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| #endif
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| } XosTimer;
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| 
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| 
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| //-----------------------------------------------------------------------------
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| // Extern declarations.
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| //-----------------------------------------------------------------------------
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| 
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| // System clock frequency in cycles per second.
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| extern uint32_t xos_clock_freq;
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| 
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| 
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| ///@{
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| //-----------------------------------------------------------------------------
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| // Functions to convert from clock cycles to time units and vice versa.
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| //
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| // Note that these are integer conversions so for example a cycle count of less
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| // than one second will convert to zero seconds.
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| //-----------------------------------------------------------------------------
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| 
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| ///  Converts CPU cycles to time in seconds.
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| ///
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| ///  \param     cycles          Number of CPU cycles.
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| ///
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| ///  \return    Equivalent number of seconds (truncated to integer).
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| static inline uint64_t
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| xos_cycles_to_secs(uint64_t cycles)
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| {
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|     return cycles / xos_clock_freq;
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| }
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| 
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| /// Converts CPU cycles to time in milliseconds.
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| ///
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| ///  \param     cycles          Number of CPU cycles.
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| ///
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| ///  \return    Equivalent number of milliseconds (truncated to integer).
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| static inline uint64_t
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| xos_cycles_to_msecs(uint64_t cycles)
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| {
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|     return (cycles * 1000) / xos_clock_freq;
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| }
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| 
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| /// Converts CPU cycles to time in microseconds.
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| ///
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| ///  \param     cycles          Number of CPU cycles.
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| ///
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| ///  \return    Equivalent number of microseconds (truncated to integer).
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| static inline uint64_t
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| xos_cycles_to_usecs(uint64_t cycles)
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| {
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|     return (cycles * 1000000) / xos_clock_freq;
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| }
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| 
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| /// Converts time in seconds to CPU cycle count.
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| ///
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| ///  \param     secs            Number of seconds.
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| ///
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| ///  \return    Equivalent number of CPU cycles.
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| static inline uint64_t
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| xos_secs_to_cycles(uint64_t secs)
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| {
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|     return secs * xos_clock_freq;
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| }
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| 
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| /// Converts time in milliseconds to CPU cycle count.
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| ///
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| ///  \param     msecs           Number of milliseconds.
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| ///
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| ///  \return    Equivalent number of CPU cycles.
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| static inline uint64_t
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| xos_msecs_to_cycles(uint64_t msecs)
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| {
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|     return (msecs * xos_clock_freq) / 1000;
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| }
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| 
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| /// Converts time in microseconds to CPU cycle count.
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| ///
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| ///  \param     usecs           Number of microseconds.
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| ///
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| ///  \return    Equivalent number of CPU cycles.
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| static inline uint64_t
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| xos_usecs_to_cycles(uint64_t usecs)
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| {
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|     return (usecs * xos_clock_freq) / 1000000;
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| }
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| ///@}
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Set system clock frequency. This is expected to be set only once, and only
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| ///  if the clock frequency is not known at compile time.
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| ///
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| ///  \param     freq            Frequency in cycles per second.
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| ///
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| ///  \return    Returns nothing.
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| ///
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| //-----------------------------------------------------------------------------
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| static inline void
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| xos_set_clock_freq(uint32_t freq)
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| {
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|     xos_clock_freq = freq;
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| }
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Get current system clock frequency.
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| ///
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| ///  \return    Returns current system clock frequency in cycles per second.
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| ///
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| //-----------------------------------------------------------------------------
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| static inline uint32_t
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| xos_get_clock_freq()
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| {
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|     return xos_clock_freq;
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| }
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Initialize timer support and start the system timer.
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| ///  This function must be called before calling any other timer function.
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| ///
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| ///  NOTE: The smaller the tick period, the more precisely delays can be
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| ///  specified using timers.  However, we also need to make the tick period
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| ///  large enough to allow time both to execute the tick timer interrupt handler
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| ///  and for the application to make reasonable forward progress.  If tick_period
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| ///  is too small, the timer interrupt may re-trigger before the timer interrupt
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| ///  handler has returned to the application, thus keeping the processor busy in
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| ///  constantly executing the timer interrupt handler without leaving any cycles
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| ///  for the application. Or, the application might get some cycles but only a 
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| ///  fraction of what is spent in the timer interrupt handler, thus severely
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| ///  impacting application performance.
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| ///
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| ///  The exact number of cycles needed to execute the timer interrupt handler
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| ///  is not specified here.  It depends on many factors (e.g. use of caches, 
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| ///  various processor configuration options, etc) and can vary by orders of
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| ///  magnitude.  Also note that the time to execute this handler is variable:
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| ///  when timers expire upon a given tick timer interrupt, their respective
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| ///  timer handler functions are called from within the interrupt handler.
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| ///
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| ///  \param     timer_num       Which Xtensa timer to use (0..2). This timer
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| ///                             must exist and be configured at level 1 or at a
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| ///                             medium-priority interrupt level (<=EXCM_LEVEL).
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| ///                             If 'timer_num' is -1, then this function will
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| ///                             automatically choose the highest priority timer
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| ///                             that is suitable for use. This value will be
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| ///                             passed to xos_system_timer_select().
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| ///
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| ///  \param     tick_period     Number of clock (CCOUNT) cycles between ticks.
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| ///                             Must range between 0 and UINT32_MAX.
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| ///                             Zero is used to specify dynamic tick (tickless)
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| ///                             mode.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_start_system_timer(int32_t timer_num, uint32_t tick_period);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Get the timer number of the system timer. Useful mainly when XOS has been
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| ///  allowed to choose its own timer via xos_start_system_timer(). Not valid if
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| ///  called before the system timer has been started.
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| ///
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| ///  \return    Returns one of XOS_SYS_TIMER_0, XOS_SYS_TIMER_1, XOS_SYS_TIMER_2
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| ///             or XOS_SYS_TIMER_EXTERNAL, or XOS_SYS_TIMER_NONE.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_get_system_timer_num(void);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Initialize timer object.
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| ///
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| ///  \param     timer           Pointer to timer event structure.
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| ///
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| ///  \return    Returns nothing.
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| ///
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| ///  NOTE: This function should not be called on a timer object once it has 
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| ///  been activated.
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| ///
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| //-----------------------------------------------------------------------------
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| void xos_timer_init(XosTimer * timer);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| //  Flags for xos_timer_start().
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| //-----------------------------------------------------------------------------
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| #define XOS_TIMER_DELTA         0x0000
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| #define XOS_TIMER_PERIODIC      0x0001
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| #define XOS_TIMER_ABSOLUTE      0x0002
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| #define XOS_TIMER_FROM_NOW      0x0000
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| #define XOS_TIMER_FROM_LAST     0x0010
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Start the timer, and when the timer expires, call the specified function
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| ///  (invoke (*fn)(arg)). If the timer is periodic, it will be automatically
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| ///  restarted when it expires.
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| ///
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| ///  The specified timer event structure must have been initialized before
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| ///  first use by calling xos_timer_init().
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| ///
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| ///  The callback function will be called in an interrupt context. Hence it is
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| ///  NOT safe to use any coprocessors in the function, including the FPU. If a
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| ///  coprocessor must be used, then its state must be saved and restored across
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| ///  its use.
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| ///
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| ///  NOTE: If you are using the timer only to wait on (via xos_timer_wait())
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| ///  then it is not necessary to specify a callback function. You should pass
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| ///  NULL for the callback function and zero for the callback argument.
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| ///
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| ///  \param     timer           Pointer to timer event structure. Must have been
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| ///                             initialized. May be active or not.
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| ///
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| ///  \param     when            When to call the function (see flags).
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| ///
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| ///  \param     flags           Set of option flags XOS_TIMER_* \n
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| ///                             The following flags are mutually exclusive:
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| ///                             - XOS_TIMER_DELTA -- when is number of cycles from
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| ///                               [see below] (default)
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| ///                             - XOS_TIMER_PERIODIC -- when is number of cycles
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| ///                               from [see below], and timer continually
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| ///                               re-triggers at that interval
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| ///                             - XOS_TIMER_ABSOLUTE -- when is absolute value of
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| ///                               cycle count \n
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| ///  \n
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| ///                             The following flags are mutually exclusive:
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| ///                             - XOS_TIMER_FROM_NOW -- *DELTA and *PERIODIC are
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| ///                               relative to now (default)
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| ///                             - XOS_TIMER_FROM_LAST -- *DELTA and *PERIODIC are
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| ///                               relative to the timer event's last specified expiry
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| ///                               time (usually in the future if active, in the past
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| ///                               if not, absolute 0 if was never activated).
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| ///
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| ///  \param     func            Function to call (called in timer interrupt context).
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| ///                             This argument is optional. Specify NULL if no function
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| ///                             is to be called.
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| ///
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| ///  \param     arg             Argument passed to callback function. Only relevant if
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| ///                             'func' is not NULL.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_timer_start(XosTimer *     timer,
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|                 uint64_t       when,
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|                 uint32_t       flags,
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|                 XosTimerFunc * func,
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|                 void *         arg);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Stop the timer and remove it from the list of active timers. Has no effect
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| ///  if the timer is not active. Any waiting threads are woken up.
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| /// 
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| ///  The timer structure must have been initialized at least once, else its
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| ///  contents are undefined and can lead to unpredictable results.
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| ///
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| ///  \param     timer           Pointer to timer object.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_timer_stop(XosTimer * timer);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Reset and restart the timer.
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| ///
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| ///  The timer is reset to go off at time "when" from now. If the timer was not
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| ///  active, it will be activated. If the timer was active, it will be restarted.
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| ///  If the timer is periodic, the period will be set to "when".
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| ///  The timer object must have been initialized at some point before this call.
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| ///
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| ///  \param     timer           Pointer to timer object.
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| ///
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| ///  \param     when            Number of cycles from now that the timer will expire.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_timer_restart(XosTimer * timer, uint64_t when);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Check if the timer is active. The timer is active if it has been started
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| ///  and not yet expired or canceled.
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| ///
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| ///  \param     timer           Pointer to timer object.
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| ///
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| ///  \return    Returns non-zero if the timer is active, else zero.
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| ///
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| //-----------------------------------------------------------------------------
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| static inline int32_t
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| xos_timer_is_active(XosTimer * timer)
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| {
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|     return timer ? timer->active : 0;
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| }
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Get the repeat period for a periodic timer. For a one-shot timer this will
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| ///  return zero. The period is reported in system clock cycles.
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| ///
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| ///  \param     timer           Pointer to timer object.
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| ///
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| ///  \return    Returns period in cycles, or zero for non-periodic timers.
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| ///
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| //-----------------------------------------------------------------------------
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| static inline uint64_t
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| xos_timer_get_period(XosTimer * timer)
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| {
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|     return timer ? timer->delta : 0;
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| }
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Set the repeat period for a periodic timer. The period must be specified
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| ///  in system clock cycles.
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| ///
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| ///  If the timer is active, the change in period does not take effect until 
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| ///  the timer expires at least once after this call.
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| ///  Note that setting a period of zero will effectively turn a periodic timer
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| ///  into a one-shot timer. Similarly, a one-shot timer can be turned into a
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| ///  periodic timer.
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| ///
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| ///  \param     timer           Pointer to timer object.
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| ///
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| ///  \param     period          Repeat period in system clock cycles.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_timer_set_period(XosTimer * timer, uint64_t period);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Get the current system cycle count. This accounts for the periodic rollover
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| ///  of the 32-bit CCOUNT cycle counter and returns a 64-bit value.
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| ///
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| ///  \return    Returns the current system cycle count.
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| ///
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| //-----------------------------------------------------------------------------
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| static inline uint64_t
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| xos_get_system_cycles(void)
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| {
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|     extern uint64_t xos_system_cycles;
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|     extern uint32_t xos_last_ccount;
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| 
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|     // xos_last_ccount was updated when xos_system_cycles was last updated.
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|     // We need to add in the number of cycles elapsed since then.
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|     return xos_system_cycles + (xos_get_ccount() - xos_last_ccount);
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| }
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Put calling thread to sleep for at least the specified number of cycles.
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| ///  The actual number of cycles spent sleeping may be larger depending upon
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| ///  the granularity of the system timer. Once the specified time has elapsed
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| ///  the thread will be woken and made ready.
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| ///
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| ///  \param     cycles          Number of system clock cycles to sleep.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_thread_sleep(uint64_t cycles);
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Put calling thread to sleep for at least the specified number of msec.
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| ///  The actual amount of time spent sleeping may be larger depending upon
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| ///  the granularity of the system timer. Once the specified time has elapsed
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| ///  the thread will be woken and made ready.
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| ///
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| ///  \return    msecs           The number of milliseconds to sleep.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| static inline int32_t
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| xos_thread_sleep_msec(uint64_t msecs)
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| {
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|     return xos_thread_sleep(xos_msecs_to_cycles(msecs));
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| }
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| 
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| 
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| //-----------------------------------------------------------------------------
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| ///
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| ///  Put calling thread to sleep for at least the specified number of usec.
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| ///  The actual amount of time spent sleeping may be larger depending upon
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| ///  the granularity of the system timer. Once the specified time has elapsed
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| ///  the thread will be woken and made ready.
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| ///
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| ///  \return    usecs           The number of microseconds to sleep.
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| ///
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| ///  \return    Returns XOS_OK on success, else error code.
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| ///
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| //-----------------------------------------------------------------------------
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| static inline int32_t
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| xos_thread_sleep_usec(uint64_t usecs)
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| {
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|     return xos_thread_sleep(xos_usecs_to_cycles(usecs));
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| }
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| 
 | |
| 
 | |
| //-----------------------------------------------------------------------------
 | |
| ///
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| ///  Wait on a timer until it expires or is cancelled. The calling thread will
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| ///  be blocked. The timer must be active.
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| ///  NOTE: This operation is only available if XOS_OPT_TIMER_WAIT is set
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| ///  to 1 in the configuration options.
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| ///
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| ///  \param     timer           Pointer to timer object.
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| ///
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| ///  \return    Returns XOS_OK on normal timeout, else an error code.
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| ///
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| //-----------------------------------------------------------------------------
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| int32_t
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| xos_timer_wait(XosTimer * timer);
 | |
| 
 | |
| 
 | |
| //-----------------------------------------------------------------------------
 | |
| // System timer control interface.
 | |
| //-----------------------------------------------------------------------------
 | |
| 
 | |
| 
 | |
| //-----------------------------------------------------------------------------
 | |
| // Defines for system timer ID.
 | |
| //-----------------------------------------------------------------------------
 | |
| #define XOS_SYS_TIMER_0             0    ///< Internal timer 0
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| #define XOS_SYS_TIMER_1             1    ///< Internal timer 1
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| #define XOS_SYS_TIMER_2             2    ///< Internal timer 2
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| #define XOS_SYS_TIMER_EXTERNAL      -2   ///< External timer
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| #define XOS_SYS_TIMER_NONE          -1   ///< No system timer selected
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| 
 | |
| 
 | |
| //-----------------------------------------------------------------------------
 | |
| ///
 | |
| ///  This function handles XOS timer tick processing. It must be called by the
 | |
| ///  timer interrupt handler on every timer interrupt. This function computes
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| ///  the time to the next tick and sets it up by calling xos_system_timer_set().
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| ///
 | |
| //-----------------------------------------------------------------------------
 | |
| void
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| xos_tick_handler(void);
 | |
| 
 | |
| 
 | |
| //-----------------------------------------------------------------------------
 | |
| ///
 | |
| ///  Selects the timer to use. The selection may be one of the internal timers
 | |
| ///  or an external timer. The default implementation selects an internal timer.
 | |
| ///  This function can be overridden to provide custom timer processing or to
 | |
| ///  support an external timer.
 | |
| ///
 | |
| ///  \param     timer_num       The internal timer number to select (0-2) or
 | |
| ///                             -1 to auto-select a timer. This parameter can
 | |
| ///                             be ignored by custom implementations that use
 | |
| ///                             an external timer.
 | |
| ///
 | |
| ///  \param     psel            Pointer to a location where the selected timer
 | |
| ///                             ID must be returned. The timer ID must be one
 | |
| ///                             of XOS_SYS_TIMER_0, XOS_SYS_TIMER_1, XOS_SYS_TIMER_2
 | |
| ///                             or XOS_SYS_TIMER_EXTERNAL.
 | |
| ///
 | |
| ///  \return    Returns XOS_OK on success, else error code.
 | |
| ///
 | |
| //-----------------------------------------------------------------------------
 | |
| int32_t
 | |
| xos_system_timer_select(int32_t timer_num, int32_t *psel);
 | |
| 
 | |
| 
 | |
| //-----------------------------------------------------------------------------
 | |
| ///
 | |
| ///  Starts the system timer and sets up the first interrupt. This function can
 | |
| ///  be overridden to provide custom timer processing or to support an external
 | |
| ///  timer.
 | |
| ///
 | |
| ///  \param     cycles          The number of CPU cycles from now when the
 | |
| ///                             first interrupt must occur.
 | |
| ///
 | |
| //-----------------------------------------------------------------------------
 | |
| void
 | |
| xos_system_timer_init(uint32_t cycles);
 | |
| 
 | |
| 
 | |
| //-----------------------------------------------------------------------------
 | |
| ///
 | |
| ///  Sets the next trigger value of the system timer. The parameter 'cycles' is
 | |
| ///  the number of CPU cycles from now when the interrupt must occur.
 | |
| ///  This function can be overridden to provide custom timer processing or to
 | |
| ///  support an external timer.
 | |
| ///
 | |
| ///  \param     cycles          The number of CPU cycles from now when the
 | |
| ///                             next interrupt must occur.
 | |
| ///
 | |
| //-----------------------------------------------------------------------------
 | |
| void
 | |
| xos_system_timer_set(uint32_t cycles);
 | |
| 
 | |
| 
 | |
| #ifdef __cplusplus
 | |
| }
 | |
| #endif
 | |
| 
 | |
| #endif  // __XOS_TIMER_H__
 | |
| 
 |