3.0 Preparation

You are to create two of logic circuits to drive one of the seven-segment displays on the Altera UP-1 board. Please see Section 5.0 for details of how to use and hook up to these boards. (In particular, note that to turn a segment on, you must drive the corresponding pin to a logical "0").

Your preparation, to be marked, should consist of the VHDL code and the simulator output for all circuits. Print out the simulation results and VHDL code for marking. Use the timing simulator for the 7128 device if you're using the student version of maxplus2.

Design a circuit that takes a four bit (X₃, X₂, X₁, X₀) input from the digital switch board (like you did in Lab #2) and drives digit #1 on the Altera board as described in the table below. Note that for the letters, some are capitalized and some are not. (The reason is that a capital B, for example, would come out the same as an 8 on a 7-segment display, so we will display a lower case b instead).

X3 X2 X1X0	Display (note the capitalization)
0000	0
0001	1
0010	2
0011	3
0100	4
0101	5
0110	6
0111	7
1000	8
1001	9
1010	A
1011	b
1100	C
1101	d
1110	E
1111	F

Determine the equations for the 7-segment display segments, and minimize them using the Karnaugh-map method described in class. Write VHDL code to represent the logic function for each segment as a boolean equation (with AND, NOT, OR etc.). Simulate and test your equations using the maxplus2 functional or timing simulation on the MAX 7128S device.

2. Design a similar circuit to the one given in part 1, except that you should use the four input switches to generate the letters of your last name. For example, if your last name is Suvanthingham, you could use code 0000 to display an S, 0001 to display a U, 0010 to display a V (or something as close to a V as you can get). Note that you can choose any code you wish for each letter. Notice also that you don't need to create two codes for a letter that appears twice in your name. For example, the letter A appears twice in Suvanthingham, but you only need to produce one code for the letter A - the intent is that you will be able to spell out your last name on the 7-segment display by entering the codes for the letters one at a time.

Fairness alert: if your last name is longer than 8 unique letters, you need only do 8 unique characters of it. If your last name is shorter than 8 characters, you must add more letters of your first name until you have coded at least 8 unique characters.

Since you will only need to do 8 codes, you can leverage the don't cares that will be available in the truth tables.