#include "stc12c5a. H
#define Timer_reload () {tl0=0x00; Th0=0xc4;} Enable to T/CInitial 10ms
#define MAX_TASKS 8//Maximum number of task slots.
unsigned char idata task_stack[max_tasks][2];//task stack. The PC pointer is 16 bits and requires 2 bytes.
unsigned char idata task_time[max_tasks]; Timing Time
unsigned char task_id=0; Current active Task number
void rtos_wait (unsigned char time)
{
Save Current task time
Task_time[task_id]=time;
Save the current breakpoint and put sp=sp-2, task switch to the next task;
Task_stack[task_id][1] =* ((unsigned char *) (SP));
sp--;
Task_stack[task_id][0] =* ((unsigned char *) (SP));
sp--;
Task number
if (++task_id = = max_tasks)
task_id = 0;
}
unsigned char a=0;
unsigned char b=0;
void Task_test ()
{
while (1)
{
a++;
Rtos_wait (100);After running, record the next address and return
a++;
}
}
void Task_test2 ()
{
while (1)
{
b++;
Rtos_wait (10);After running, record the next address and return
b++;
}
}
void Timer0init () @18.432mhz
{
AUXR &= 0x7F; Timer Clock 12T mode
Tmod &= 0xF0; Set Timer mode
Tmod |= 0x01; Set Timer mode
TL0 = 0x00; Set the timing initial value
TH0 =0xc4; Set timing Initial value 10ms
TF0 = 0; Clear the TF0 flag
TR0 = 1; Timer 0 Start Timer
Et0=1;
Ea=1;
}
void Main ()
{
Timer0init ();
Task_test ();
Task_test2 ();
while (1);
}
void Rwcl () Task time to switch back to real time
{
From the timing time minus 1, look for which task to, task time to real-time switch back to
unsigned char i;
for (i=0;i<max_tasks;i++)
{
if (Task_time[i])
{
task_time[i]--;
if (task_time[i]==0)
sp=task_stack[i]+1;
}
}
}
void Tm0_isr () Interrupt 1 using 1
{
Timed Time overloading
Timer_reload ();
RWCL (); Task time to switch back to real time
}
51 Series Small OS Essence simple implementation 6 C language version to be improved
