MODM7AE70 blocking millisecond delay

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zealott
Posts: 28
Joined: Thu Oct 30, 2008 1:15 am

MODM7AE70 blocking millisecond delay

Post by zealott » Sun Nov 01, 2020 9:12 am

Hi,

Quick code for a high resolution blocking delay.
Paste code and call delayms(10) for a 10ms delay. It blocks the calling task/prio for that time.
Seems to work fine, tweaks or fixes (if any) appreciated.

Cheers,
John

Code: Select all

#include <nbrtos.h>
#include <IntervalTimer.h>

/* variables -----------------------------------------------------------------*/
OS_SEM delayms_Semaphores[OS_MAX_PRIOS];		// semaphores for each prio
uint8_t delayms_active[OS_MAX_PRIOS]={0};		// is current PRIO blocking?
volatile int32_t delayms_Timers[OS_MAX_PRIOS]; 		// we set this to eg, 200 for 200ms delay
bool delayms_initialized = false;			// first time init

/* delayms_callback - callback for every tick of the timer -------------------*/
void delayms_callback()
{
	for(int i=0;i<OS_MAX_PRIOS;i++)
	{
		if(delayms_active[i])
		{
			if(delayms_Timers[i]<=0)	// we use signed int and <=0 to prevent a possible deadlock
			{
				delayms_active[i] = 0;
				delayms_Semaphores[i].Post();
			} else delayms_Timers[i]--;
		}
	}
}

/* delayms_init - initializes timer ------------------------------------------*/
void delayms_init()
{
	IntervalInterruptCallback(&delayms_callback, 1000);
	delayms_initialized = true;
}

/* delayms - parameter is milliseconds to block the current PRIO -------------*/
void delayms(uint16_t ms)
{
	if(delayms_initialized==false)
		delayms_init();

	// 1ms can be between 0ms and 1ms
	delayms_Timers[nPrioOfCurTask] = ms;
	delayms_active[nPrioOfCurTask] = 1;
	delayms_Semaphores[nPrioOfCurTask].Init(0);
	delayms_Semaphores[nPrioOfCurTask].Pend();

	return;
}



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