Cosmetic changed, updated README files, improved comments
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@ -54,6 +54,27 @@
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* logic when the interval timer expires.
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*
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****************************************************************************/
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/****************************************************************************
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* SAMA5 Timer Usage
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*
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* This current implementation uses two timers: A one-shot timer to provide
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* the timed events and a free running timer to provide the current time.
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* Since timers are a limited resource, that could be an issue on some
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* systems.
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*
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* We could do the job with a single timer if we were to keep the single
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* timer in a free-running at all times. The SAMA5 timer/counters have
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* 32-bit counters with the capability to generate a compare interrupt when
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* the timer matches a compare value but also to continue counting without
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* stopping (giving another, different interrupt when the timer rolls over
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* from 0xffffffff to zero). So we could potentially just set the compare
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* at the number of ticks you want PLUS the current value of timer. Then
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* you could have both with a single timer: An interval timer and a free-
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* running counter with the same timer!
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*
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* Patches are welcome!
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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@ -2332,6 +2332,8 @@ TRNG and /dev/random
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Tickless OS
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===========
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Background
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----------
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By default, a NuttX configuration uses a periodic timer interrupt that
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drives all system timing. The timer is provided by architecture-specifi
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code that calls into NuttX at a rate controlled by CONFIG_USEC_PER_TICK.
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@ -2368,6 +2370,8 @@ Tickless OS
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OS event will occur, program the interval time and wait for it to fire.
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When the interval time fires, then the scheduled activity is performed.
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Configuration
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-------------
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The following configuration options will enable support for the Tickless
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OS for the SAMA5D platforms using TC0 channels 0-3 (other timers or
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timer channels could be used making the obvious substitutions):
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@ -2385,6 +2389,25 @@ Tickless OS
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CONFIG_SAMA5_TICKLESS_FREERUN=1 : Selects TC0 channel 1 for the free-
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: running timer
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SAMA5 Timer Usage
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-----------------
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This current implementation uses two timers: A one-shot timer to
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provide the timed events and a free running timer to provide the current
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time. Since timers are a limited resource, that could be an issue on
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some systems.
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We could do the job with a single timer if we were to keep the single
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timer in a free-running at all times. The SAMA5 timer/counters have
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32-bit counters with the capability to generate a compare interrupt when
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the timer matches a compare value but also to continue counting without
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stopping (giving another, different interrupt when the timer rolls over
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from 0xffffffff to zero). So we could potentially just set the compare
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at the number of ticks you want PLUS the current value of timer. Then
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you could have both with a single timer: An interval timer and a free-
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running counter with the same timer!
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Patches are welcome!
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I2S Audio Support
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=================
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@ -2648,6 +2648,8 @@ Touchscreen Testing
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Tickless OS
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===========
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Background
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----------
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By default, a NuttX configuration uses a periodic timer interrupt that
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drives all system timing. The timer is provided by architecture-specifi
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code that calls into NuttX at a rate controlled by CONFIG_USEC_PER_TICK.
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@ -2684,6 +2686,8 @@ Tickless OS
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OS event will occur, program the interval time and wait for it to fire.
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When the interval time fires, then the scheduled activity is performed.
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Configuration
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-------------
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The following configuration options will enable support for the Tickless
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OS for the SAMA5D platforms using TC0 channels 0-3 (other timers or
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timer channels could be used making the obvious substitutions):
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@ -2701,6 +2705,25 @@ Tickless OS
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CONFIG_SAMA5_TICKLESS_FREERUN=1 : Selects TC0 channel 1 for the free-
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: running timer
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SAMA5 Timer Usage
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-----------------
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This current implementation uses two timers: A one-shot timer to
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provide the timed events and a free running timer to provide the current
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time. Since timers are a limited resource, that could be an issue on
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some systems.
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We could do the job with a single timer if we were to keep the single
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timer in a free-running at all times. The SAMA5 timer/counters have
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32-bit counters with the capability to generate a compare interrupt when
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the timer matches a compare value but also to continue counting without
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stopping (giving another, different interrupt when the timer rolls over
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from 0xffffffff to zero). So we could potentially just set the compare
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at the number of ticks you want PLUS the current value of timer. Then
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you could have both with a single timer: An interval timer and a free-
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running counter with the same timer!
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Patches are welcome!
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OV2640 Camera Interface
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=======================
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@ -3112,6 +3112,8 @@ TM7000 LCD/Touchscreen
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Tickless OS
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===========
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Background
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----------
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By default, a NuttX configuration uses a periodic timer interrupt that
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drives all system timing. The timer is provided by architecture-specifi
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code that calls into NuttX at a rate controlled by CONFIG_USEC_PER_TICK.
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@ -3148,6 +3150,8 @@ Tickless OS
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OS event will occur, program the interval time and wait for it to fire.
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When the interval time fires, then the scheduled activity is performed.
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Configuration
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-------------
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The following configuration options will enable support for the Tickless
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OS for the SAMA5D platforms using TC0 channels 0-3 (other timers or
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timer channels could be used making the obvious substitutions):
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@ -3165,6 +3169,25 @@ Tickless OS
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CONFIG_SAMA5_TICKLESS_FREERUN=1 : Selects TC0 channel 1 for the free-
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: running timer
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SAMA5 Timer Usage
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-----------------
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This current implementation uses two timers: A one-shot timer to
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provide the timed events and a free running timer to provide the current
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time. Since timers are a limited resource, that could be an issue on
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some systems.
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We could do the job with a single timer if we were to keep the single
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timer in a free-running at all times. The SAMA5 timer/counters have
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32-bit counters with the capability to generate a compare interrupt when
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the timer matches a compare value but also to continue counting without
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stopping (giving another, different interrupt when the timer rolls over
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from 0xffffffff to zero). So we could potentially just set the compare
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at the number of ticks you want PLUS the current value of timer. Then
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you could have both with a single timer: An interval timer and a free-
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running counter with the same timer!
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Patches are welcome!
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SAMA4D4-EK Configuration Options
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=================================
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