begriffs open source - cmsis-freertos/blob - Demo/ColdFire_MCF52233_Eclipse/RTOSDemo/FreeRTOS_Tick

1 /*

4

5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

6

7 ***************************************************************************

8 * *

9 * FreeRTOS provides completely free yet professionally developed, *

10 * robust, strictly quality controlled, supported, and cross *

11 * platform software that has become a de facto standard. *

12 * *

13 * Help yourself get started quickly and support the FreeRTOS *

14 * project by purchasing a FreeRTOS tutorial book, reference *

15 * manual, or both from: http://www.FreeRTOS.org/Documentation *

16 * *

17 * Thank you! *

18 * *

19 ***************************************************************************

20

21 This file is part of the FreeRTOS distribution.

22

23 FreeRTOS is free software; you can redistribute it and/or modify it under

24 the terms of the GNU General Public License (version 2) as published by the

25 Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.

26

27 >>! NOTE: The modification to the GPL is included to allow you to !<<

28 >>! distribute a combined work that includes FreeRTOS without being !<<

29 >>! obliged to provide the source code for proprietary components !<<

30 >>! outside of the FreeRTOS kernel. !<<

31

32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY

33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

34 FOR A PARTICULAR PURPOSE. Full license text is available from the following

35 link: http://www.freertos.org/a00114.html

36

37 1 tab == 4 spaces!

38

39 ***************************************************************************

40 * *

41 * Having a problem? Start by reading the FAQ "My application does *

42 * not run, what could be wrong?" *

43 * *

44 * http://www.FreeRTOS.org/FAQHelp.html *

45 * *

46 ***************************************************************************

47

48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,

49 license and Real Time Engineers Ltd. contact details.

50

51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,

52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS

53 compatible FAT file system, and our tiny thread aware UDP/IP stack.

54

55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High

56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS

57 licenses offer ticketed support, indemnification and middleware.

58

59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety

60 engineered and independently SIL3 certified version for use in safety and

61 mission critical applications that require provable dependability.

62

63 1 tab == 4 spaces!

64 */

65

66 #include "FreeRTOS.h"

67 #include "task.h"

68

69 /* Constants used to configure the interrupts. */

70 #define portPRESCALE_VALUE 64

71 #define portPRESCALE_REG_SETTING ( 5 << 8 )

72 #define portPIT_INTERRUPT_ENABLED ( 0x08 )

73 #define configPIT0_INTERRUPT_VECTOR ( 55 )

74

75 /*

76 * FreeRTOS.org requires two interrupts - a tick interrupt generated from a

77 * timer source, and a spare interrupt vector used for context switching.

78 * The configuration below uses PIT0 for the former, and vector 16 for the

79 * latter. **IF YOUR APPLICATION HAS BOTH OF THESE INTERRUPTS FREE THEN YOU DO

80 * NOT NEED TO CHANGE ANY OF THIS CODE** - otherwise instructions are provided

81 * here for using alternative interrupt sources.

82 *

83 * To change the tick interrupt source:

84 *

85 * 1) Modify vApplicationSetupInterrupts() below to be correct for whichever

86 * peripheral is to be used to generate the tick interrupt.

87 *

88 * 2) Change the name of the function __cs3_isr_interrupt_119() defined within

89 * this file to be correct for the interrupt vector used by the timer peripheral.

90 * The name of the function should contain the vector number, so by default vector

91 * number 119 is being used.

92 *

93 * 3) Make sure the tick interrupt is cleared within the interrupt handler function.

94 * Currently __cs3_isr_interrupt_119() clears the PIT0 interrupt.

95 *

96 * To change the spare interrupt source:

97 *

98 * 1) Modify vApplicationSetupInterrupts() below to be correct for whichever

99 * interrupt vector is to be used. Make sure you use a spare interrupt on interrupt

100 * controller 0, otherwise the register used to request context switches will also

101 * require modification. By default vector 16 is used which is free on most MCF52xxx

102 * devices.

103 *

104 * 2) Change the definition of configYIELD_INTERRUPT_VECTOR within FreeRTOSConfig.h

105 * to be correct for your chosen interrupt vector.

106 *

107 * 3) Change the name of the function __cs3_isr_interrupt_80() within portasm.S

108 * to be correct for whichever vector number is being used. By default interrupt

109 * controller 0 vector number 16 is used, which corresponds to vector number 80.

110 */

111 void vApplicationSetupInterrupts( void )

112 {

113 const unsigned short usCompareMatchValue = ( ( configCPU_CLOCK_HZ / portPRESCALE_VALUE ) / configTICK_RATE_HZ );

114

115 /* Configure interrupt priority and level and unmask interrupt for PIT0. */

116 MCF_INTC0_ICR55 = ( 1 | ( configKERNEL_INTERRUPT_PRIORITY << 3 ) );

117 MCF_INTC0_IMRH &= ~( MCF_INTC_IMRH_INT_MASK55 );

118

119 /* Do the same for vector 16 (interrupt controller 0). I don't think the

120 write to MCF_INTC0_IMRH is actually required here but is included for

121 completeness. */

122 MCF_INTC0_ICR16 = ( 0 | ( configKERNEL_INTERRUPT_PRIORITY << 3 ) );

123 MCF_INTC0_IMRH &= ~( MCF_INTC_IPRL_INT16 );

124

125 /* Configure PIT0 to generate the RTOS tick. */

126 MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;

127 MCF_PIT0_PCSR = ( portPRESCALE_REG_SETTING | MCF_PIT_PCSR_PIE | MCF_PIT_PCSR_RLD | MCF_PIT_PCSR_EN );

128 MCF_PIT0_PMR = usCompareMatchValue;

129 }

130 /*-----------------------------------------------------------*/

131

132 void __attribute__ ((interrupt)) __cs3_isr_interrupt_119( void )

133 {

134 unsigned long ulSavedInterruptMask;

135

136 /* Clear the PIT0 interrupt. */

137 MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;

138

139 /* Increment the RTOS tick. */

140 ulSavedInterruptMask = portSET_INTERRUPT_MASK_FROM_ISR();

141 if( xTaskIncrementTick() != pdFALSE )

142 {

143 taskYIELD();

144 }

145 portCLEAR_INTERRUPT_MASK_FROM_ISR( ulSavedInterruptMask );

146 }