Reference no: EM132306757

The in-person explanation of how the circuit works will be a short (about 5 minute) informal interview between you and your workshop demonstrator. During this interview you will demonstrate your circuit and convey your understanding of all aspects of the completed circuit. This interview will be held in your workshop in Week 12 and will also serve as a way to receive individual feedback on your work.

Task Description:

You are to build (and test) the following digital logic circuit in the Logisim simulator and write a short report that describes your circuit. The maximum mark that you are able to achieve on the assignment will be determined by the difficulty of the circuit you decide to build (Option 1 or Option 2, see below).

Circuit Options:

It may be better to have a fully functional and neatly drawn simple circuit than a complex one that is messily constructed and/or does not function properly.

Labelling

You must label each circuit and template that you construct with the Annotation tool and ensure that all the inputs are labelled as instructed in this sheet. Each circuit and subcircuit/template must be labelled with:
1. Your name
2. Your student number
3. An appropriate label for each input
4. An appropriate label for each output
5. An appropriate label for each subcircuit/template
Note: Be careful, before submission, test if your circuit works as required.

Templates/Subcircuits
You will be required to use templates (Logisim calls these subcircuits) to simplify the overall circuit design.

Testing
You will need to test various possible combinations for the inputs C1, C2, C3, D1, D2 and D3 and check if the desired output is obtained (for Part A). You do not need to submit your tests.

For Part B, you will also have to test the cases where the elevator is no longer able to be used if there is a security lockdown.

Report
Your report (6-8 pages including diagrams) must have the following sections:

1. Your details: Name, student number, and email address
2. Circuit Function: A brief (100-200 words for each part) description of the function of each separate part of your circuit describing in your own words how that part of the circuit operates. This should be split up into sections that relate to the different components (templates/subcircuits) in the overall circuit.
3. Circuit diagrams: A diagram of your circuit including all templates/subcircuits and their contents. You must draw this diagram yourself using the Logisim logic simulator. To include a circuit in your report, please take a screen shot of the circuit and paste the screenshot into your report. Copying and pasting from the lecture notes or other sources is NOT permitted.
4. Truth table: Show all possible inputs and outputs for the Current floor
(C) and the Destination floor (D). The column headings in your truth table should correspond to the labels on your circuit diagram.

In-person Interview
To be held in your workshop in week 12. You will be asked to clearly demonstrate your circuit and your understanding of its operation to your workshop demonstrator.

Requirements:
For this assignment you must implement a simple simulation of an elevator. The elevator has two inputs. Input 1 (C) represents the Current floor (0-7). Input 2 (D) represents the Destination floor to move to (0-7). The elevator is only allowed to stop on Floors 1, 2, 3, 5, and 7. Floors 0, 4 and 6 are private and the elevator will not stop there even if the button for that floor is pressed. The elevator movement is successful if C = 1, 2, 3, 5, or 7, D = 1, 2, 3, 5, or 7, and C ≠ D. Any other values will result in an elevator movement error and the elevator will not move.

Example 1: The current floor (C) is 2 and the floor we want to move to
(D) is 5. In this case the move to floor 5 is successful.

Example 2: The current floor (C) is 2 and the floor we want to move to
(D) is 4. In this case D is 4 (a private floor) and there is an elevator movement error. The elevator does not move.

Example 3: The current floor (C) is 4 and the floor we want to move to
(S) is 2. In this case the starting floor is 4 (a private floor) and there is an elevator movement error. The elevator does not move

Note: These are just a couple of examples. There are (many) more cases that result in successful or unsuccessful elevator moves. Your circuit must correctly show a successful or unsuccessful elevator move for each possible case.

The Current floor (C) will be represented by three inputs (3 bits). The three C inputs are named as C1, C2, and C3. The table below shows the assignment of bits to each C value for C1, C2, and C3.

The Destination floor (D) that we want to move to will be represented by three inputs (3 bits). The three D inputs are named as D1, D2, and D3. The table below shows the assignment of bits to each D value for D1, D2, and D3.

C and D Inputs

Part A
Circuit Option 1: Part A Only:
The implementation for this part must use only the three basic logic gates
(AND, OR, NOT) with maximum 2 inputs.

You are required to implement a circuit where the user (you) can input a value for the Current floor (C) using value (C1, C2, and C3) and a Destination floor to move to (D) using value (D1, D2, and D3) and the circuit decodes the C1, C2, C3 and D1, D2, D3 values using a decoder (see lecture notes) made up of only the permitted logic gates to determine if the requirement for moving in the requirements section on page 4 is met.

The output will be a single LED labelled Successful which is lit if C = 1, 2, 3, 5, or 7, D = 1, 2, 3, 5, or 7, and C ≠ D. The LED is not lit for any other values of C and D.

Part B
Circuit Option 2: Part A and Part B:
For this part, the elevator has a security mechanism that locks the elevator and stops it from moving if a certain number (N) of unsuccessful attempts to move are made. An unsuccessful attempt to move is when the elevator tries to move from a private floor or to a private floor, or if the elevator tries to move to the floor it is currently on (eg: C=3, D=3). Floors 0, 4 and 6 are private floors. The number N ranges from 1 to 7 and must be set via a combination of three separate inputs: N1, N2, and N3. An N value of 0 is not allowed and you need to set N to be non-zero (1..7) before setting elevator floor values.

Using the same circuit as Part A, add additional circuitry to count how many successful and unsuccessful elevator moves have been made. Each time an unsuccessful elevator move is made, add 1 to the number of unsuccessful elevator moves. Each time a successful elevator move is made, add 1 to the number of successful elevator moves.

Elevator security lockdown (elevator no longer able to be moved):
If the number of unsuccessful elevator moves is equal to N then an LED labelled "Elevator lockdown" is lit, and the circuit is permanently locked. No matter the changes to the input after this happens, the "Elevator lockdown" LED will remain lit and cannot be turned off.

Values for N1, N2, N3

For Part B only, you may use only the three basic logic gates (AND, OR, NOT) with maximum 2 inputs, as well as the more advanced counter, comparator, and DFLIP-FLOP circuits (only those three) from the Logisim circuit library. You may also use a constant (4) to compare against successful elevator moves, and it is permissible to use a constant (0) to isolate the special case where N = 0. The prebuilt DFLIP-FLOP circuit can be used to ‘remember' some information. You can also combine the 3 inputs for N into a single 3-bit input by setting the data bits to 3. Note that this is not permissible for the C or D inputs.

Note:
For Part B you will need to add a button that is pressed by you after the Current floor (C) and Destination floor to move to (D) have been entered. This is to avoid counting while you are adjusting the input pins for the C and D input pins (C1, C2, C3, D1, D2, and D3).

This extra section is required to be completed regardless of whether you chose to complete Part A or Part B and should be about 400-600 words in length.

In this section, give a detailed description of the following:

1. How you would need to change the circuit if the Current floor (C) and Destination floor (D) were for a high-rise elevator with 97 floors with floors 12-20, 35-40 and 97 also private floors?

2. How you would need to change the circuit for the 97 floor high-rise from the previous question if it was permissible to move from a private floor, but it was still not permissible to move to a private floor?

Attachment:- Computer Systems and Networks.rar