Word Generator latency?

[Buiosu]

Hi,

For one project at my studies I have to simulate the return-to-zero encoder. At first attempt I thought about using clock signal that triggers the word generator and is also used to AND with the word generator output. I'm using MultiSim ver. 10.0.429.

I'm getting one issue that I don't understand...

Please take a look at the image - there is a small delay between slopes of the first signal (clock) and second signal (data, out of the word generator). I thought - and somebody told me - that it is a race hazard. But when I remove the AND gate and just put the signals from both components to the oscilloscope I get the same problem, maybe a little bit shorter delay.

The Digital Simulation Settings is set to "ideal".

What am I doing wrong?

Regards,

Tomasz

[Kokosinela]

Hi, Tomasz!

As you probably know, simulation is a mathematical way of emulating the behavior of a circuit.  Although Multisim makes simulation intuitively easy-to-use,

the technology underlying the speed and accuracy of the simulation, as well as its ease-of-use, is complex.

So, every result that components generates depends of the model that is used for simulation. As you mentioned, one type of models is ideal.The “Ideal” option simulates your circuit in the way that it does not take into account variances in digital power and internal tolerances. Still, it does not mean that model taht is used will give "ideal signal".

So, I think that your statement about race hazards is correct. Also, another fact that measuring signals directly from circuit gives similar results, indicates that most probably reason for this is model that is used for word generator.

Hope I helped.

Best regards,

Sofija Poledica