Tested on G2553 Launchpad with IAR, I recommend G2955 with 1K RAM if you want more than 3 task #include "msp430.h" #include "common.h" //=========================(C) Tony Philipsson 2016 ======================= funcpnt const taskpnt[]={ task1, task2, task3, // <- PUT YOUR TASKS HERE }; const int stacksize[tasks] = {28}; // a blank value defaults to 24 stack words //========================================================================= int taskstackpnt[tasks]; unsigned int taskdelay[tasks]; char taskrun; int main( void ) { WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer if (CALBC1_8MHZ != 0xff){ // erased by mistake? BCSCTL1 = CALBC1_8MHZ; // Set DCO to factory calibrate 1MHz DCOCTL = CALDCO_8MHZ; } int* multistack = (int*) __get_SP_register(); int i=0; while(i<tasks-1){ int j = stacksize[i]; if (!j) j = 24; multistack -= j; *(multistack) = (int) taskpnt[++i]; // prefill in PC *(multistack-1) = GIE; // prefill in SR taskstackpnt[i] = (int) multistack-26; // needs 12 dummy push words } WDTCTL = WDTPW+WDTTMSEL+WDTCNTCL; // 4ms interval at 8MHz smclk IE1 |= WDTIE; __bis_SR_register(GIE); asm ("br &taskpnt"); // indirect jmp to first task } //============= TASK SWITCHER ISR ============= #pragma vector = WDT_VECTOR __raw __interrupt void taskswitcher(void) { asm ("push R15\n push R14\n push R13\n push R12\n" "push R11\n push R10\n push R9\n push R8\n" "push R7\n push R6\n push R5\n push R4"); taskstackpnt[taskrun] = __get_SP_register(); if (++taskrun == tasks) taskrun = 0; __set_SP_register(taskstackpnt[taskrun]); asm ("pop R4\n pop R5\n pop R6\n pop R7\n" "pop R8\n pop R9\n pop R10\n pop R11\n" "pop R12\n pop R13\n pop R14\n pop R15"); } #include "msp430.h" #include "common.h" __task void task1(void){ P1DIR |= BIT0; while(1){ __delay_cycles(800000); P1OUT |= BIT0; __delay_cycles(800000); P1OUT &=~BIT0; } } #include "msp430.h" #include "common.h" __task void task2(void){ P1DIR |= BIT6; while(1){ __delay_cycles(1200000); P1OUT |= BIT6; __delay_cycles(1200000); P1OUT &=~BIT6; } } #include "msp430.h" #include "common.h" unsigned int fibo(int); __task void task3(void){ int temp = 0; while(1){ fibo(++temp); } } unsigned int fibo(int n){ if (n < 2) return n; else return (fibo(n-1) + fibo(n-2)); } #ifndef COMMON_H_ #define COMMON_H_ #define tasks (sizeof(taskpnt)/2) __task void task1(void); __task void task2(void); __task void task3(void); typedef __task void (*funcpnt)(void); #endif