1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
/*
* FreeRTOS Kernel V10.2.1
* Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
#include "FreeRTOS.h"
#include "task.h"
__declspec(interrupt:0) void vPIT0InterruptHandler( void );
/* Constants used to configure the interrupts. */
#define portPRESCALE_VALUE 64
#define portPRESCALE_REG_SETTING ( 5 << 8 )
#define portPIT_INTERRUPT_ENABLED ( 0x08 )
#define configPIT0_INTERRUPT_VECTOR ( 55 )
/*
* FreeRTOS.org requires two interrupts - a tick interrupt generated from a
* timer source, and a spare interrupt vector used for context switching.
* The configuration below uses PIT0 for the former, and vector 16 for the
* latter. **IF YOUR APPLICATION HAS BOTH OF THESE INTERRUPTS FREE THEN YOU DO
* NOT NEED TO CHANGE ANY OF THIS CODE** - otherwise instructions are provided
* here for using alternative interrupt sources.
*
* To change the tick interrupt source:
*
* 1) Modify vApplicationSetupInterrupts() below to be correct for whichever
* peripheral is to be used to generate the tick interrupt. The name of the
* handler function (currently vPIT0InterruptHandler()) should also be updated
* to indicate which peripheral is generating the interrupt.
*
* 2) Make sure the interrupt source is cleared within the interrupt handler function.
* Currently vPIT0InterruptHandler() clears the PIT0 interrupt.
*
* 3) Update the vector table within mcf5225x_vectors.s to install the tick
* interrupt handler in the correct vector position.
*
* To change the spare interrupt source:
*
* 1) Modify vApplicationSetupInterrupts() below to be correct for whichever
* interrupt vector is to be used. Make sure you use a spare interrupt on interrupt
* controller 0, otherwise the register used to request context switches will also
* require modification.
*
* 2) Change the definition of configYIELD_INTERRUPT_VECTOR within FreeRTOSConfig.h
* to be correct for your chosen interrupt vector.
*
* 3) Update the vector table within mcf5225x_vectors.s to install the handler
* _vPortYieldISR() in the correct vector position (by default vector number 16 is
* used).
*/
void vApplicationSetupInterrupts( void )
{
const unsigned short usCompareMatchValue = ( ( configCPU_CLOCK_HZ / portPRESCALE_VALUE ) / configTICK_RATE_HZ );
/* Configure interrupt priority and level and unmask interrupt for PIT0. */
MCF_INTC0_ICR55 = ( 1 | ( configKERNEL_INTERRUPT_PRIORITY << 3 ) );
MCF_INTC0_IMRH &= ~( MCF_INTC_IMRH_INT_MASK55 );
/* Do the same for vector 63 (interrupt controller 0. I don't think the
write to MCF_INTC0_IMRH is actually required here but is included for
completeness. */
MCF_INTC0_ICR16 = ( 0 | configKERNEL_INTERRUPT_PRIORITY << 3 );
MCF_INTC0_IMRL &= ~( MCF_INTC_IMRL_INT_MASK16 | 0x01 );
/* Configure PIT0 to generate the RTOS tick. */
MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;
MCF_PIT0_PCSR = ( portPRESCALE_REG_SETTING | MCF_PIT_PCSR_PIE | MCF_PIT_PCSR_RLD | MCF_PIT_PCSR_EN );
MCF_PIT0_PMR = usCompareMatchValue;
}
/*-----------------------------------------------------------*/
__declspec(interrupt:0) void vPIT0InterruptHandler( void )
{
unsigned long ulSavedInterruptMask;
/* Clear the PIT0 interrupt. */
MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;
/* Increment the RTOS tick. */
ulSavedInterruptMask = portSET_INTERRUPT_MASK_FROM_ISR();
if( xTaskIncrementTick() != pdFALSE )
{
taskYIELD();
}
portCLEAR_INTERRUPT_MASK_FROM_ISR( ulSavedInterruptMask );
}
|
