Re-implement the LPC18xx and SmartFusion2 run time stats implementation to use the free running Cortex-M cycle counter in place of the systick.

Correct the run-time stats counter implementation in the RZ demo.
Guard against run time counters going backwards in tasks.c.


git-svn-id: http://svn.code.sf.net/p/freertos/code/trunk@1946 1d2547de-c912-0410-9cb9-b8ca96c0e9e2

1 files changed, 44 insertions, 37 deletions

diff --git a/FreeRTOS/Demo/CORTEX_SmartFusion2_M2S050_SoftConsole/RTOSDemo/RunTimeStatsTimer.c b/FreeRTOS/Demo/CORTEX_SmartFusion2_M2S050_SoftConsole/RTOSDemo/RunTimeStatsTimer.c
index 0ce8bc630..ba195276f 100644
--- a/FreeRTOS/Demo/CORTEX_SmartFusion2_M2S050_SoftConsole/RTOSDemo/RunTimeStatsTimer.c
+++ b/FreeRTOS/Demo/CORTEX_SmartFusion2_M2S050_SoftConsole/RTOSDemo/RunTimeStatsTimer.c
@@ -74,65 +74,72 @@
 

 /* FreeRTOS includes. */

 #include "FreeRTOS.h"

-#include "task.h"

 

 /* Utility functions to implement run time stats on Cortex-M CPUs.  The collected

 run time data can be viewed through the CLI interface.  See the following URL for

 more information on run time stats:

 http://www.freertos.org/rtos-run-time-stats.html */

 

-/* Used in the run time stats calculations. */

-static uint32_t ulClocksPer10thOfAMilliSecond = 0UL;

+/* Addresses of registers in the Cortex-M debug hardware. */

+#define rtsDWT_CYCCNT 			( *( ( unsigned long * ) 0xE0001004 ) )

+#define rtsDWT_CONTROL 			( *( ( unsigned long * ) 0xE0001000 ) )

+#define rtsSCB_DEMCR 			( *( ( unsigned long * ) 0xE000EDFC ) )

+#define rtsTRCENA_BIT			( 0x01000000UL )

+#define rtsCOUNTER_ENABLE_BIT	( 0x01UL )

+

+/* Simple shift divide for scaling to avoid an overflow occurring too soon.  The

+number of bits to shift depends on the clock speed. */

+#define runtimeSLOWER_CLOCK_SPEEDS	( 70000000UL )

+#define runtimeSHIFT_13				13

+#define runtimeOVERFLOW_BIT_13		( 1UL << ( 32UL - runtimeSHIFT_13 ) )

+#define runtimeSHIFT_14				14

+#define runtimeOVERFLOW_BIT_14		( 1UL << ( 32UL - runtimeSHIFT_14 ) )

 

+/*-----------------------------------------------------------*/

 

 void vConfigureTimerForRunTimeStats( void )

 {

-	/* How many clocks are there per tenth of a millisecond? */

-	ulClocksPer10thOfAMilliSecond = configCPU_CLOCK_HZ / 10000UL;

+	/* Enable TRCENA. */

+	rtsSCB_DEMCR = rtsSCB_DEMCR | rtsTRCENA_BIT;

+

+	/* Reset counter. */

+	rtsDWT_CYCCNT = 0;

+

+	/* Enable counter. */

+	rtsDWT_CONTROL = rtsDWT_CONTROL | rtsCOUNTER_ENABLE_BIT;

 }

 /*-----------------------------------------------------------*/

 

 uint32_t ulGetRunTimeCounterValue( void )

 {

-uint32_t ulSysTickCounts, ulTickCount, ulReturn;

-const uint32_t ulSysTickReloadValue = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;

-volatile uint32_t * const pulCurrentSysTickCount = ( ( volatile uint32_t *) 0xe000e018 );

-volatile uint32_t * const pulInterruptCTRLState = ( ( volatile uint32_t *) 0xe000ed04 );

-const uint32_t ulSysTickPendingBit = 0x04000000UL;

-

-	/* NOTE: There are potentially race conditions here.  However, it is used

-	anyway to keep the examples simple, and to avoid reliance on a separate

-	timer peripheral. */

-

-

-	/* The SysTick is a down counter.  How many clocks have passed since it was

-	last reloaded? */

-	ulSysTickCounts = ulSysTickReloadValue - *pulCurrentSysTickCount;

+static unsigned long ulLastCounterValue = 0UL, ulOverflows = 0;

+unsigned long ulValueNow;

 

-	/* How many times has it overflowed? */

-	ulTickCount = xTaskGetTickCountFromISR();

+	ulValueNow = rtsDWT_CYCCNT;

 

-	/* Is there a SysTick interrupt pending? */

-	if( ( *pulInterruptCTRLState & ulSysTickPendingBit ) != 0UL )

+	/* Has the value overflowed since it was last read. */

+	if( ulValueNow < ulLastCounterValue )

 	{

-		/* There is a SysTick interrupt pending, so the SysTick has overflowed

-		but the tick count not yet incremented. */

-		ulTickCount++;

-

-		/* Read the SysTick again, as the overflow might have occurred since

-		it was read last. */

-		ulSysTickCounts = ulSysTickReloadValue - *pulCurrentSysTickCount;

+		ulOverflows++;

 	}

+	ulLastCounterValue = ulValueNow;

 

-	/* Convert the tick count into tenths of a millisecond.  THIS ASSUMES

-	configTICK_RATE_HZ is 1000! */

-	ulReturn = ( ulTickCount * 10UL ) ;

+	/* Cannot use configCPU_CLOCK_HZ directly as it may itself not be a constant

+	but instead map to a variable that holds the clock speed. */

 

-	/* Add on the number of tenths of a millisecond that have passed since the

-	tick count last got updated. */

-	ulReturn += ( ulSysTickCounts / ulClocksPer10thOfAMilliSecond );

+	/* There is no prescale on the counter, so simulate in software. */

+	if( configCPU_CLOCK_HZ < runtimeSLOWER_CLOCK_SPEEDS )

+	{

+		ulValueNow >>= runtimeSHIFT_13;

+		ulValueNow += ( runtimeOVERFLOW_BIT_13 * ulOverflows );

+	}

+	else

+	{

+		ulValueNow >>= runtimeSHIFT_14;

+		ulValueNow += ( runtimeOVERFLOW_BIT_14 * ulOverflows );

+	}

 

-	return ulReturn;

+	return ulValueNow;

 }

 /*-----------------------------------------------------------*/