app.c

μC／OS—ⅡV：2.80 对 ATMega256 单片机的移植程序代码。

/*
*************************************************************************************************************
*                                                uC/OS-II
*                                          The Real-Time Kernel
*
*                                         ATmega256  Sample code
*
* File : APP.C
* By   : Jean J. Labrosse
*************************************************************************************************************
*/

#include <includes.h>


/*
**************************************************************************************************************
*                                               VARIABLES
**************************************************************************************************************
*/

INT32U  AppTickISRCtr;

OS_STK  AppTaskStartStk[OS_TASK_START_STK_SIZE];

/*
**************************************************************************************************************
*                                           FUNCTION PROTOTYPES
**************************************************************************************************************
*/

        void  main(void);

static  void  AppTaskStart(void *p_arg);
static  void  AppTaskCreate(void);
static  void  AppTickInit(void);

#if OS_VIEW_MODULE > 0
static  void  AppTerminalRx(INT8U rx_data);
#endif

/*
**************************************************************************************************************
*                                                MAIN
**************************************************************************************************************
*/

void  main (void)
{
    INT8U  err;

                                                /* ATmega256 oscillator settings                       */
    CLKPR             = 0x80;                   /* Set internal oscillator to DIV by 1, 8 MHz OSC      */
    CLKPR             = 0x00;

    /*---- Any initialization code prior to calling OSInit() goes HERE --------------------------------*/

    OSTaskStkSize     = OS_TASK_IDLE_STK_SIZE;  /* Setup the Idle and Statistics Task sizes            */
    OSTaskStkSizeHard = OS_TASK_IDLE_STK_SIZE_HARD;
    OSInit();                                   /* Initialize "uC/OS-II, The Real-Time Kernel"         */

    /*---- Any initialization code before starting multitasking ---------------------------------------*/

    OSTaskStkSize     = OS_TASK_START_STK_SIZE;
    OSTaskStkSizeHard = OS_TASK_START_STK_SIZE_HARD;
    OSTaskCreateExt(AppTaskStart,
                    (void *)0,
                    (OS_STK *)&AppTaskStartStk[OSTaskStkSize - 1],
                    OS_TASK_START_PRIO,
                    OS_TASK_START_PRIO,
                    (OS_STK *)&AppTaskStartStk[OSTaskStkSizeHard],
                    OSTaskStkSize - OSTaskStkSizeHard,
                    (void *)0,
                    OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR);


#if (OS_TASK_NAME_SIZE > 14) && (OS_TASK_STAT_EN > 0)
    OSTaskNameSet(OS_TASK_START_PRIO, "Start Task", &err);
#endif

    /*---- Create any other task you want before we start multitasking --------------------------------*/

    OSStart();                              /* Start multitasking (i.e. give control to uC/OS-II)      */
}

/*
*********************************************************************************************************
*                                          STARTUP TASK
*
* Description : This is an example of a startup task.  As mentioned in the book's text, you MUST
*               initialize the ticker only once multitasking has started.
*
* Arguments   : p_arg   is the argument passed to 'AppTaskStart()' by 'OSTaskCreate()'.
*
* Notes       : 1) The first line of code is used to prevent a compiler warning because 'p_arg' is not
*                  used.  The compiler should not generate any code for this statement.
*********************************************************************************************************
*/

static  void  AppTaskStart (void *p_arg)
{
    INT8U  i;


    (void)p_arg;                            /* Prevent compiler warnings                               */

    BSP_Init();                             /* Initialize the Board Support Package                    */

    AppTickInit();                          /* Initialize the tick interrupts needed by uC/OS-II       */

#if OS_TASK_STAT_EN > 0
    OSStatInit();                           /* Start stats task                                        */
#endif

#if OS_VIEW_MODULE > 0
    OSView_Init(38400);                     /* Initialize uC/OS-View if module is present              */
    OSView_TerminalRxSetCallback(AppTerminalRx);
#endif

    AppTaskCreate();                        /* Create other application tasks                          */

    LED_Off(0);
    while (TRUE) {
        for (i = 1; i <= 8; i++) {
            LED_On(i);
            OSTimeDly(OS_TICKS_PER_SEC / 20);
            LED_Off(i);
        }
        for (i = 7; i > 1; i--) {
            LED_On(i);
            OSTimeDly(OS_TICKS_PER_SEC / 20);
            LED_Off(i);
        }
    }
}

/*
*********************************************************************************************************
*                                      TERMINAL WINDOW CALLBACK
*********************************************************************************************************
*/

#if OS_VIEW_MODULE > 0
static  void  AppTerminalRx (INT8U rx_data)
{
}
#endif

/*
*********************************************************************************************************
*                                    CREATE APPLICATION TASKS
*********************************************************************************************************
*/

static  void  AppTaskCreate (void)
{
}

/*
*********************************************************************************************************
*                                       TICKER INITIALIZATION
*
* Description : This function is called to initialize uC/OS-II's tick source (typically a timer generating
*               interrupts every 1 to 100 mS).
*
* Arguments   : none
*********************************************************************************************************
*/

static  void  AppTickInit (void)
{
    AppTickISRCtr =    0;
    TCCR0A        = 0x02;                               /* Set TIMER0 prescaler to CTC Mode, CLK/1024  */
    TCCR0B        = 0x05;                               /* Set CLK/1024 Prescale                       */
    TCNT0         =    0;                               /* Start TCNT at 0 for a new cycle             */
    OCR0A         = CPU_CLK_FREQ / OS_TICKS_PER_SEC / 1024 - 1;
    TIFR0        |= 0x02;                               /* Clear  TIMER0 compare Interrupt Flag        */
    TIMSK0       |= 0x02;                               /* Enable TIMER0 compare Interrupt             */
}


/*
*********************************************************************************************************
*                                         TIMER #0 IRQ HANDLER
*
* Description : This function handles the timer interrupt that is used to generate TICKs for uC/OS-II.
*
* Arguments   : none
*
* Note(s)     : 1) There is no need to clear the interrupt since this is done automatically in Output
*                  Compare mode when the ISR is executed.
*********************************************************************************************************
*/

void  AppTickISR_Handler (void)
{
    AppTickISRCtr++;
    OSTimeTick();                       /* If the interrupt is from the tick source, call OSTimeTick() */
}