sample_c.c

同事写的一个内核

#include <REG51F.H>
#include "k51.h"

unsigned char idata sig1;

unsigned char idata mut1;

unsigned int  count_t1_intrs;

#pragma rb(0)
void task1()
{
    for (;;)
    {
        TI = 0;
        SBUF = '1';
        k51_sleep(0x10);
    }
}

#pragma rb(1)
void task2()
{
    // this task waits on a signal witch can be signaled by isr.
    for (;;)
    {
        k51_signal_wait(&sig1);

        k51_mutex_wait(&mut1);

        // send "Timer1 signal."
        TI = 0;
        SBUF = 'T';
        k51_sleep(1);

        TI = 0;
        SBUF = 'i';
        k51_sleep(1);

        TI = 0;
        SBUF = 'm';
        k51_sleep(1);

        TI = 0;
        SBUF = 'e';
        k51_sleep(1);

        TI = 0;
        SBUF = 'r';
        k51_sleep(1);

        TI = 0;
        SBUF = '1';
        k51_sleep(1);

        TI = 0;
        SBUF = ' ';
        k51_sleep(1);

        TI = 0;
        SBUF = 'S';
        k51_sleep(1);

        TI = 0;
        SBUF = 'i';
        k51_sleep(1);

        TI = 0;
        SBUF = 'g';
        k51_sleep(1);

        TI = 0;
        SBUF = 'n';
        k51_sleep(1);

        TI = 0;
        SBUF = 'a';
        k51_sleep(1);

        TI = 0;
        SBUF = 'l';
        k51_sleep(1);

        TI = 0;
        SBUF = '.';
        k51_sleep(1);


        // send "CRLF"
        TI = 0;
        SBUF = 0xd;
        k51_sleep(1);

        TI = 0;
        SBUF = 0xa;

        k51_mutex_release(&mut1);
    }
}

#pragma rb(2)
void task3()
{
    unsigned char i;
    for (;;)
    {
        k51_sleep(60);

        k51_mutex_wait(&mut1);

        for (i=0; i<6; i++)
        {
            TI = 0;
            SBUF = '3';
            k51_sleep(1);
        }
        TI = 0;
        SBUF = 0xd;
        k51_sleep(1);

        TI = 0;
        SBUF = 0xa;

        k51_mutex_release(&mut1);
    }
}

#pragma rb(3)
void task4()
{
    unsigned char i;
    for (;;)
    {
        k51_sleep(80);

        k51_mutex_wait(&mut1);

        for (i=0; i<8; i++)
        {
            TI = 0;
            SBUF = '4';
            k51_sleep(1);
        }
        TI = 0;
        SBUF = 0xd;
        k51_sleep(1);

        TI = 0;
        SBUF = 0xa;

        k51_mutex_release(&mut1);
    }
}

#pragma rb(3)
void main()
{
    unsigned char i;
    count_t1_intrs = 0;

    k51_signal_init(&sig1);

    k51_mutex_init(&mut1);

    k51_init();

    task1_init();           /* task will really active after an interrupt       */
                            /* because PRIO_MAIN is set to 1, this function     */
                            /* returns error_prio, failed                       */
    task2_init();
    task3_init();
    task4_init();

    TMOD = 0x11;            /* timer1 mode1...timer0 mode1                      */
    TR1  = 1;
    TR0  = 1;
    IE   = 0x8a;            /* enable timer1 and timer0 intr                    */

    for (;;)
    {
        k51_sleep(20);

        k51_mutex_wait(&mut1);

        for (i=0; i<2; i++)
        {
            TI = 0;
            SBUF = '1';
            k51_sleep(1);
        }
        TI = 0;
        SBUF = 0xd;
        k51_sleep(1);

        TI = 0;
        SBUF = 0xa;

        k51_mutex_release(&mut1);
    }
}

// timer0 intr provides system timer
void isr_timer0()
{
    k51_tick();             // k51_tick() can be called at any level
}

// timer1 interrupt service function.
// it sends signal to task2, and makes it active.
void isr_timer1()
{
    count_t1_intrs++;

    if (count_t1_intrs >= 300)
    {
        count_t1_intrs = 0;
        k51_signal_send(&sig1);
    }

}