What I often do for verification is to reconstruct the logic in a spreadsheet using the Boolean functions. Create an array of input variables and feed them into the logic function and check the output array with the truth table. You can also use this approach for verifying the operation of state machines. However, not having access to a logic simulator I don't know whether this method is simpler than building the gate logic in a simulator.Could you explain in a defferent way?
You can't expect to always have people that you can ask to check your work for you -- if you could, then the people paying YOU to solve a problem would probably simply offer to pay those people in the first place. So you need to develop the skills and practices to check your own work for correctness. Fortunately checking the validity of a solution is usually a lot simpler than coming up with the solution in the first place.I didn't get you. Could you explain in a defferent way?
When I first saw it I had the same reaction, but this is actually a mistake that isn't a mistake.I've glanced through all the equations on post #42. One mistake I found is on your f(B)=A'.B + A.B'
This is supposed to be an XOR gate with inputs A and B. Not sure why there are 2 inverters and 2 AND gates before the XOR. Unless that XOR is actually an OR gate?
Allen
No, the problem is that he has the counter set up to run backwards.hi ham,
IF I am reading your plotted waveform correctly, you seem to have no Reset pulse to the counter/s.?
So the first clock pulse sets all 3 F/F outputs High, ie: logical '1'
The Reset pulse should Reset all 3 F/F's, '0', before you start clocking.
In the simulation you probably don't need it since the sim will probably initialize your flip flops to zero in order to get the sim to even converge. But in the real world you need to reset the counter because, in the real world, it will power up in an effectively random state. So what you typically do is provide a POR (power-on reset) circuit that holds the reset pin active for a short period of time after power is applied using a simple RC filter. In the simulator you can achieve the same goal by simply applying a one-time pulse to the rest pin at the beginning of the simulation.Then how to connect the reset ?
Hi WB,In the simulation you probably don't need it since the sim will probably initialize your flip flops to zero in order
hi ham,Then how to connect the reset ?
by Aaron Carman
by Duane Benson
by Duane Benson
by Aaron Carman