Difference between revisions of "CSC270 Lab 5"
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===Experiment=== | ===Experiment=== | ||
| − | * Disconnect the clock inputs from the CLOCK signal, and connect them to GND. This way your sequencer is frozen. | + | * Disconnect the clock inputs from the CLOCK signal, and connect them to GND. This way your sequencer is frozen and will not change state. |
* Cycle the power OFF/ON a few times and record what state the sequence starts in. Compare with the sequencer of other people in the class. Do the sequencer always start in the same state? Why? | * Cycle the power OFF/ON a few times and record what state the sequence starts in. Compare with the sequencer of other people in the class. Do the sequencer always start in the same state? Why? | ||
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==Part 2: Controllable Sequencer== | ==Part 2: Controllable Sequencer== | ||
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| + | Implement and wire-up an ''UP/DOWN 2-bit counter''. | ||
| + | |||
| + | An up/down counter is a counter with an outside control signal, UP/DWN' which, when 1 forces the counter to count up, i.e. its outputs go 00, 01, 10, 11, 00, etc. When UP/DWN' is 0, the counter counts down, i.e. its outputs go 00, 11, 10, 01, 00, etc. | ||
| + | |||
| + | Add a CLR' outside signal that will allow the user to clear the counter asynchronously, forcing its two bits to 0 0. | ||
| + | |||
| + | ==Part 3: Up-Down LED display== | ||
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| + | Do not disconnect your Up/Down counter, and connect its Q outputs to a 2-to-4 decoder. Connect the 4 outputs of the decoder to 4 LEDs and make the LED pattern go LEFT or RIGHT depending on the UP/DWN' signal. | ||
| + | |||
| + | Be imaginative when it comes to using/finding/creating a 2-to-4 decoder!!! | ||
Latest revision as of 10:45, 4 March 2009
Back to the weekly schedule
--D. Thiebaut 13:39, 4 March 2009 (UTC)
Contents
LAB #5: More Sequential Circuits
© D. Thiebaut, 2009
Part 1: Starting states, and Hard Reset
Setup
- Implement the 2-bit/4-state sequencer with the following equations:
D1 = Q1 xor Q0 D0 = not Q1
- Connect the CLR and PR to Vcc.
- Connect Q0 and Q1 to LEDs
- Verify that your circuit works when the 1Hz signal is connected to the CLOCK inputs.
Experiment
- Disconnect the clock inputs from the CLOCK signal, and connect them to GND. This way your sequencer is frozen and will not change state.
- Cycle the power OFF/ON a few times and record what state the sequence starts in. Compare with the sequencer of other people in the class. Do the sequencer always start in the same state? Why?
Hard Reset
- You are going to connect some of the CLR and/or PR inputs of the flip-flop so that you can always force (reset) the sequencer to be in State 10 (Q1=1, Q0=0).
- A single momentary switch should activate the CLR/PR inputs you selected.
- Reconnect the clock inputs to the CLOCK signal.
- Turn your sequencer ON and verify that you can always reset it by activating the momentary switch
Part 2: Controllable Sequencer
Implement and wire-up an UP/DOWN 2-bit counter.
An up/down counter is a counter with an outside control signal, UP/DWN' which, when 1 forces the counter to count up, i.e. its outputs go 00, 01, 10, 11, 00, etc. When UP/DWN' is 0, the counter counts down, i.e. its outputs go 00, 11, 10, 01, 00, etc.
Add a CLR' outside signal that will allow the user to clear the counter asynchronously, forcing its two bits to 0 0.
Part 3: Up-Down LED display
Do not disconnect your Up/Down counter, and connect its Q outputs to a 2-to-4 decoder. Connect the 4 outputs of the decoder to 4 LEDs and make the LED pattern go LEFT or RIGHT depending on the UP/DWN' signal.
Be imaginative when it comes to using/finding/creating a 2-to-4 decoder!!!
