IAR PowerPac RTOS User Guide

** demo program to illustrate the use of resource semaphores*/OS_STACKPTR int StackMain[100], StackClock[50];OS_TASK TaskMain,TaskClock;OS_SEMA SemaLCD;void TaskClock(void) {char t=-1;char s[] = "00:00";while(1) {while (TimeSec==t) Delay(10);t= TimeSec;s[4] = TimeSec%10+'0';s[3] = TimeSec/10+'0';s[1] = TimeMin%10+'0';s[0] = TimeMin/10+'0';OS_Use(&SemaLCD); /* Make sure nobody else uses LCD */LCD_Write(10,0,s);OS_Unuse(&SemaLCD); /* Release LCD */}}void TaskMain(void) {signed char pos ;LCD_Write(0,0,"Software tools by IAR Systems ! ") ;OS_Delay(2000);while (1) {for ( pos=14 ; pos >=0 ; pos-- ) {OS_Use(&SemaLCD); /* Make sure nobody else uses LCD */LCD_Write(pos,1,"train "); /* Draw train */OS_Unuse(&SemaLCD); /* Release LCD */OS_Delay(500);}OS_Use(&SemaLCD); /* Make sure nobody else uses LCD */LCD_Write(0,1," ") ;OS_Unuse(&SemaLCD); /* Release LCD */}}void InitTask(void) {OS_CREATERSEMA(&SemaLCD); /* Creates resource semaphore */OS_CREATETASK(&TaskMain, 0, Main, 50, StackMain);OS_CREATETASK(&TaskClock, 0, Clock, 100, StackClock);}In most applications, the routines that access a resource should automatically call OS_Use() and OS_Unuse() so thatwhen using the resource you do not have to worry about it and can use it just as you would in a single-task system. Thefollowing is an example of how to implement a resource into the routines that actually access the display:/** Simple example when accessing single line dot matrix LCD*/OS_RSEMA RDisp; /* Define resource semaphore */void UseDisp() { /* Simple routine to be called before using display */OS_Use(&RDisp);}void UnuseDisp() { /* Simple routine to be called after using display */OS_Unuse(&RDisp);}void DispCharAt(char c, char x) {UseDisp();LCDGoto(x, y);LCDWrite1(ASCII2LCD(c));UnuseDisp();}void DISPInit(void) {OS_CREATERSEMA(&RDisp);}50IAR PowerPac RTOSfor ARM CoresPPRTOS-2