Hi, I'm a C++ programmer and don't know much about assembly(though I'd like to learn in the near future). I'm writing on this forum since I need of a time delay optimized function..accurate to nearly the millisecond(Zen Timer is accurate to the microsecond I think).first off, to know why I need precise accuracy in this function, down to the exact millisecond is because I am trying to produce a frequency through my parallel port. I timed the call and return of the _outp()(function to write to the port in VSC++6.0) to be around 1/200,000th of a second. I only need my program to be exact to the 1/1000th of a second so that isn't much of a time consumer. On the other hand, the Sleep(ms) function is a MAJOR time consumer. I can only achieve at most 100Hz doing this:
while(1){
_outp(0x00378, 0x01); //Switch pin 0 to High
Sleep(1);
_outp(0x00378, 0x00); //Switch pin 0 to Low
Sleep(1);
}
The Supposed result should be that it pauses for 1 ms between switching from on to off, meaning that it does a cycle(on off) in 2 ms. This theoretically mean that it would give a frequency of 1000/2 per second or 500Hz.But it gives me 100Hz, 100 cycles a second at most!
and no, I don't think the while loop has anything to do with it since I batch process it, doing it 10 times before repeating a while.(I even experimented with no while, doing it 100 times)
I tried making my own delay function using clock() but the calls to clock() take Significantly longer than the calls to Sleep(). I'm thinking Sleep might be coded in assembly.
I need help finding an assembly written function to be used with C++ or such that might be able to help me make near precise frequencies. I know Micheal Abrash's Zen Timer does some pretty accurate calculations. Can someone show me a way to do this? Thanks!
while(1){
_outp(0x00378, 0x01); //Switch pin 0 to High
Sleep(1);
_outp(0x00378, 0x00); //Switch pin 0 to Low
Sleep(1);
}
The Supposed result should be that it pauses for 1 ms between switching from on to off, meaning that it does a cycle(on off) in 2 ms. This theoretically mean that it would give a frequency of 1000/2 per second or 500Hz.But it gives me 100Hz, 100 cycles a second at most!
and no, I don't think the while loop has anything to do with it since I batch process it, doing it 10 times before repeating a while.(I even experimented with no while, doing it 100 times)
I tried making my own delay function using clock() but the calls to clock() take Significantly longer than the calls to Sleep(). I'm thinking Sleep might be coded in assembly.
I need help finding an assembly written function to be used with C++ or such that might be able to help me make near precise frequencies. I know Micheal Abrash's Zen Timer does some pretty accurate calculations. Can someone show me a way to do this? Thanks!
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