Overview
In this project I was tasked with designing a sixty second counter within the Multisim software. Some requirements were that it needed to reset to zero-zero right after 59 is displayed, that there be a reset-to-zero switch, and that the clock input be 1 Hz.
Constraints:
Two 7-segment Common Cathode displays must be used and require a multiplexed signal.
The ones place must be controlled by a synchronous, 0-9, 74LS163 counter.
The tens place must be controlled by an asynchronous, 0-5, J/K Flip-Flop counter.
Constraints:
Two 7-segment Common Cathode displays must be used and require a multiplexed signal.
The ones place must be controlled by a synchronous, 0-9, 74LS163 counter.
The tens place must be controlled by an asynchronous, 0-5, J/K Flip-Flop counter.
Multisim Implementation
The ones place display is above the tens place display in the image below.
This project differs from the Deli Counter project because this project uses a combination of a synchronous circuit and an asynchronous circuit in the design, while the Deli Counter only utilized asynchronous counters. Also, the Deli Counter was more complex because of what you had to make the counter do, like having a controlled clock and the counter having to stop and hold its count at 80.
Conclusion
Questions:
What is the difference between Asynchronous counters and Synchronous counters?
The main difference between the two is that every part in a synchronous counter that requires a clocked input shares the same clock input, while an asynchronous counter's components with clock inputs are strung together with only the first component being connected to the main clock. This means asynchronous counters have delay and a ripple effects while synchronous counters do not have those issues.
What is the difference between a 163 chip and a 193 chip?
Both can have a specified starting and ending number but the 163 can only count up while the 193 only counts down.
Did any of your classmates come up with a different solution?
No, I don't think so. We had limited options to achieve our goal due to the requirements.
My Method:
First I read over the paper that gave us the problem statement and the requirements so I would have them in mind while designing. The I opened the Multisim software and looked back at previous worksheets to remind myself how to wire a 74LS163 to be a 4-bit synchronous counter. Once I understood this I began focusing on the ones place counter first. What I do when building in multisim is I place all the components I will be wiring in the project first so I don't forget something I would need to add if I added each part as I got to wiring them, and this helped me wire the whole circuit quicker. Once I finished the ones place counter in multisim and tested it the first time, it did not work, so I trouble-shot and found rather quickly that the reason the simulation was crashing was that too much power was going into the displays, so I put 220 ohm resister on every 7-segment display input. Now that the first counter worked I moved on to the tens place, and I successfully completed it in a short amount of time due to skills learned in the Deli Counter project using J/K Flip-Flop counters. Finally, the last thing I did was add the reset switch to the whole circuit so that the timer would go back to 0-0 if the switch was flipped.
What is the difference between Asynchronous counters and Synchronous counters?
The main difference between the two is that every part in a synchronous counter that requires a clocked input shares the same clock input, while an asynchronous counter's components with clock inputs are strung together with only the first component being connected to the main clock. This means asynchronous counters have delay and a ripple effects while synchronous counters do not have those issues.
What is the difference between a 163 chip and a 193 chip?
Both can have a specified starting and ending number but the 163 can only count up while the 193 only counts down.
Did any of your classmates come up with a different solution?
No, I don't think so. We had limited options to achieve our goal due to the requirements.
My Method:
First I read over the paper that gave us the problem statement and the requirements so I would have them in mind while designing. The I opened the Multisim software and looked back at previous worksheets to remind myself how to wire a 74LS163 to be a 4-bit synchronous counter. Once I understood this I began focusing on the ones place counter first. What I do when building in multisim is I place all the components I will be wiring in the project first so I don't forget something I would need to add if I added each part as I got to wiring them, and this helped me wire the whole circuit quicker. Once I finished the ones place counter in multisim and tested it the first time, it did not work, so I trouble-shot and found rather quickly that the reason the simulation was crashing was that too much power was going into the displays, so I put 220 ohm resister on every 7-segment display input. Now that the first counter worked I moved on to the tens place, and I successfully completed it in a short amount of time due to skills learned in the Deli Counter project using J/K Flip-Flop counters. Finally, the last thing I did was add the reset switch to the whole circuit so that the timer would go back to 0-0 if the switch was flipped.