自学教程：C++ vPortSetupTimerInterrupt函数代码示例

/* * See header file for description. */BaseType_t xPortStartScheduler( void ){	/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */	*(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;	*(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Start the first task. */	vPortStartFirstTask();	/* Should never get here as the tasks will now be executing!  Call the task	exit error function to prevent compiler warnings about a static function	not being called in the case that the application writer overrides this	functionality by defining configTASK_RETURN_ADDRESS. */	prvTaskExitError();	/* Should not get here! */	return 0;}

/* * See header file for description. */portBASE_TYPE xPortStartScheduler( void ){	/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */	portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;	portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Ensure the VFP is enabled - it should be anyway. */	prvEnableVFP();	/* Lazy save always. */	*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS;	/* Start the first task. */	prvStartFirstTask();	/* Should not get here! */	return 0;}

/* * See header file for description. */BaseType_t xPortStartScheduler( void ){	/* This port can be used on all revisions of the Cortex-M7 core other than	the r0p1 parts.  r0p1 parts should use the port from the	/source/portable/GCC/ARM_CM7/r0p1 directory. */	configASSERT( SCB->CPUID != portCORTEX_M0_r0p0_ID );	/* Make PendSV the lowest priority interrupts. */	NVIC_SetPriority(PendSV_IRQn, configKERNEL_INTERRUPT_PRIORITY);	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Finally this port requires SEVONPEND to be active */	SCB->SCR |= SCB_SCR_SEVONPEND_Msk;	/* Start the first task. */	vPortStartFirstTask();	/* Should never get here as the tasks will now be executing!  Call the task	exit error function to prevent compiler warnings about a static function	not being called in the case that the application writer overrides this	functionality by defining configTASK_RETURN_ADDRESS. */	prvTaskExitError();	/* Should not get here! */	return 0;}

/* * See header file for description. */portBASE_TYPE xPortStartScheduler( void ){	/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.	See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */	configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );	/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */	portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;	portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Ensure the VFP is enabled - it should be anyway. */	vPortEnableVFP();	/* Lazy save always. */	*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS;	/* Start the first task. */	prvPortStartFirstTask();	/* Should not get here! */	return 0;}

/* * See header file for description. */portBASE_TYPE xPortStartScheduler( void ){	/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.	See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */	configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );	#if( configASSERT_DEFINED == 1 )	{		volatile unsigned long ulOriginalPriority;		volatile char * const pcFirstUserPriorityRegister = ( volatile char * const ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );		/* Determine the maximum priority from which ISR safe FreeRTOS API		functions can be called.  ISR safe functions are those that end in		"FromISR".  FreeRTOS maintains separate thread and ISR API functions to		ensure interrupt entry is as fast and simple as possible.		Save the interrupt priority value that is about to be clobbered. */		ulOriginalPriority = *pcFirstUserPriorityRegister;		/* Write the configMAX_SYSCALL_INTERRUPT_PRIORITY value to an interrupt		priority register. */		*pcFirstUserPriorityRegister = configMAX_SYSCALL_INTERRUPT_PRIORITY;		/* Read back the written priority to obtain its value as seen by the		hardware, which will only implement a subset of the priority bits. */		ucMaxSysCallPriority = *pcFirstUserPriorityRegister;		/* Restore the clobbered interrupt priority register to its original		value. */		*pcFirstUserPriorityRegister = ulOriginalPriority;	}	#endif /* conifgASSERT_DEFINED */	/* Make PendSV and SysTick the lowest priority interrupts. */	portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;	portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Ensure the VFP is enabled - it should be anyway. */	vPortEnableVFP();	/* Lazy save always. */	*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS;	/* Start the first task. */	prvPortStartFirstTask();	/* Should not get here! */	return 0;}

/* * See header file for description. */portBASE_TYPE xPortStartScheduler( void ){	/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */	*(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;	*(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Start the first task. */	vPortStartFirstTask();	/* Should not get here! */	return 0;}

/* * See header file for description. */BaseType_t xPortStartScheduler( void ){	/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.	See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */	configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );	/* This port can be used on all revisions of the Cortex-M7 core other than	the r0p1 parts.  r0p1 parts should use the port from the	/source/portable/GCC/ARM_CM7/r0p1 directory. */	configASSERT( portCPUID != portCORTEX_M7_r0p1_ID );	configASSERT( portCPUID != portCORTEX_M7_r0p0_ID );	#if( configASSERT_DEFINED == 1 )	{		volatile uint32_t ulOriginalPriority;		volatile uint8_t * const pucFirstUserPriorityRegister = ( uint8_t * ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );		volatile uint8_t ucMaxPriorityValue;		/* Determine the maximum priority from which ISR safe FreeRTOS API		functions can be called.  ISR safe functions are those that end in		"FromISR".  FreeRTOS maintains separate thread and ISR API functions to		ensure interrupt entry is as fast and simple as possible.		Save the interrupt priority value that is about to be clobbered. */		ulOriginalPriority = *pucFirstUserPriorityRegister;		/* Determine the number of priority bits available.  First write to all		possible bits. */		*pucFirstUserPriorityRegister = portMAX_8_BIT_VALUE;		/* Read the value back to see how many bits stuck. */		ucMaxPriorityValue = *pucFirstUserPriorityRegister;		/* The kernel interrupt priority should be set to the lowest		priority. */		configASSERT( ucMaxPriorityValue == ( configKERNEL_INTERRUPT_PRIORITY & ucMaxPriorityValue ) );		/* Use the same mask on the maximum system call priority. */		ucMaxSysCallPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY & ucMaxPriorityValue;		/* Calculate the maximum acceptable priority group value for the number		of bits read back. */		ulMaxPRIGROUPValue = portMAX_PRIGROUP_BITS;		while( ( ucMaxPriorityValue & portTOP_BIT_OF_BYTE ) == portTOP_BIT_OF_BYTE )		{			ulMaxPRIGROUPValue--;			ucMaxPriorityValue <<= ( uint8_t ) 0x01;		}		/* Shift the priority group value back to its position within the AIRCR		register. */		ulMaxPRIGROUPValue <<= portPRIGROUP_SHIFT;		ulMaxPRIGROUPValue &= portPRIORITY_GROUP_MASK;		/* Restore the clobbered interrupt priority register to its original		value. */		*pucFirstUserPriorityRegister = ulOriginalPriority;	}	#endif /* conifgASSERT_DEFINED */	/* Make PendSV and SysTick the lowest priority interrupts. */	portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;	portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Ensure the VFP is enabled - it should be anyway. */	prvEnableVFP();	/* Lazy save always. */	*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS;	/* Start the first task. */	prvStartFirstTask();	/* Should not get here! */	return 0;}

/* * See header file for description. */portBASE_TYPE xPortStartScheduler( void ){	/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.	See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */	configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );	#if( configASSERT_DEFINED == 1 )	{		volatile unsigned long ulOriginalPriority;		volatile char * const pcFirstUserPriorityRegister = ( volatile char * const ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );		volatile unsigned char ucMaxPriorityValue;		/* Determine the maximum priority from which ISR safe FreeRTOS API		functions can be called.  ISR safe functions are those that end in		"FromISR".  FreeRTOS maintains separate thread and ISR API functions to		ensure interrupt entry is as fast and simple as possible.		Save the interrupt priority value that is about to be clobbered. */		ulOriginalPriority = *pcFirstUserPriorityRegister;		/* Determine the number of priority bits available.  First write to all		possible bits. */		*pcFirstUserPriorityRegister = portMAX_8_BIT_VALUE;		/* Read the value back to see how many bits stuck. */		ucMaxPriorityValue = *pcFirstUserPriorityRegister;		/* Use the same mask on the maximum system call priority. */		ucMaxSysCallPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY & ucMaxPriorityValue;		/* Calculate the maximum acceptable priority group value for the number		of bits read back. */		ulMaxPRIGROUPValue = portMAX_PRIGROUP_BITS;		while( ( ucMaxPriorityValue & portTOP_BIT_OF_BYTE ) == portTOP_BIT_OF_BYTE )		{			ulMaxPRIGROUPValue--;			ucMaxPriorityValue <<= ( unsigned char ) 0x01;		}		/* Shift the priority group value back to its position within the AIRCR		register. */		ulMaxPRIGROUPValue <<= portPRIGROUP_SHIFT;		ulMaxPRIGROUPValue &= portPRIORITY_GROUP_MASK;		/* Restore the clobbered interrupt priority register to its original		value. */		*pcFirstUserPriorityRegister = ulOriginalPriority;	}	#endif /* conifgASSERT_DEFINED */	/* Make PendSV and SysTick the lowest priority interrupts. */	portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;	portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Start the first task. */	prvPortStartFirstTask();	/* Should not get here! */	return 0;}

/* * See header file for description. */BaseType_t xPortStartScheduler( void ){	/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.	See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */	configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );	#if( configASSERT_DEFINED == 1 )	{		volatile uint32_t ulOriginalPriority;		volatile uint8_t * const pucFirstUserPriorityRegister = ( volatile uint8_t * const ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );		volatile uint8_t ucMaxPriorityValue;		/* Determine the maximum priority from which ISR safe FreeRTOS API		functions can be called.  ISR safe functions are those that end in		"FromISR".  FreeRTOS maintains separate thread and ISR API functions to		ensure interrupt entry is as fast and simple as possible.		Save the interrupt priority value that is about to be clobbered. */		ulOriginalPriority = *pucFirstUserPriorityRegister;		/* Determine the number of priority bits available.  First write to all		possible bits. */		*pucFirstUserPriorityRegister = portMAX_8_BIT_VALUE;		/* Read the value back to see how many bits stuck. */		ucMaxPriorityValue = *pucFirstUserPriorityRegister;		/* Use the same mask on the maximum system call priority. */		ucMaxSysCallPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY & ucMaxPriorityValue;		/* Calculate the maximum acceptable priority group value for the number		of bits read back. */		ulMaxPRIGROUPValue = portMAX_PRIGROUP_BITS;		while( ( ucMaxPriorityValue & portTOP_BIT_OF_BYTE ) == portTOP_BIT_OF_BYTE )		{			ulMaxPRIGROUPValue--;			ucMaxPriorityValue <<= ( uint8_t ) 0x01;		}		/* Shift the priority group value back to its position within the AIRCR		register. */		ulMaxPRIGROUPValue <<= portPRIGROUP_SHIFT;		ulMaxPRIGROUPValue &= portPRIORITY_GROUP_MASK;		/* Restore the clobbered interrupt priority register to its original		value. */		*pucFirstUserPriorityRegister = ulOriginalPriority;	}	#endif /* conifgASSERT_DEFINED */	/* Make PendSV and SysTick the lowest priority interrupts. */	portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;	portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;	/* Start the timer that generates the tick ISR.  Interrupts are disabled	here already. */	vPortSetupTimerInterrupt();	/* Initialise the critical nesting count ready for the first task. */	uxCriticalNesting = 0;	/* Ensure the VFP is enabled - it should be anyway. */	vPortEnableVFP();	/* Lazy save always. */	*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS;	/* Start the first task. */	prvPortStartFirstTask();	/* Should never get here as the tasks will now be executing!  Call the task	exit error function to prevent compiler warnings about a static function	not being called in the case that the application writer overrides this	functionality by defining configTASK_RETURN_ADDRESS. */	prvTaskExitError();	/* Should not get here! */	return 0;}