//
// example 4: task synchronization
// descriptions: The first task wait for a semaphore,when the semaphore is Realeased,
//               this task turn on LEDs one by one. 
//               The second task sends a semaphore at the rate of 0.5 second. 
// author: Taiyun Wang 
// date: 2003/2/22
///////////////////////////////////////////////////////////////////////////

#include "sposvar.h"
#include "spos.h"

int err;					//Error No
int t1stack[25];			//Task 1 stack
int t2stack[25];			//Task 2 stack
HEvent sem;					//Event handle

volatile unsigned int *P_IOB_BUFFER =(unsigned int*)(0x7006);	//Port B data register
volatile unsigned int *P_IOB_DIR =(unsigned int*)(0x7007);		//Port B direction register
volatile unsigned int *P_IOB_ATTRIB = (unsigned int*)(0x7008);	//Port B attribute register

main()
{
	void Task1();
	SpSInit();
	*P_IOB_DIR = 0XFFFF;						//Set Port B output
	*P_IOB_ATTRIB = 0XFFFF;						//Set Port B attribute
	err = SpSTaskCreate(Task1,0,t1stack+24,1);	//Create first task
	sem = SpSSemCreate(0);						//Create semaphore
	SpSStart();									//Start kernel
}
void Task1()				//Task one
{
    void Task2();
    unsigned int i = 1;
	err = SpSTaskCreate(Task2,0,t2stack+24,2);	//Create second task
   	while(1) {
		for(i = 1;i<0x100;i<<=1) {
           SpSSemPend(sem,0);					//Waiting semaphore
           *P_IOB_BUFFER = i;
		}
   }
}

void Task2()
{
	while(1) {
        SpSSemPost(sem);						//Realease semaphore
        SpSTimeDly(32);							//Delay 64 tick
 	}
}