Complete problem 3.12 from the textbook. Space for work provided on the following page.
3.12. A numeric keypad (numpad) generates a 4-bit code as shown in Fig. 3.29. We want to design a logic circuit that converts each 4-bit code to an array of 7 LEDs called 7-segment display as shown in Fig. 3.29. A LED is ON if it is given a logic value of 1. A LED is OFF if it is given the logic value of 0. Complete the truth table for each output abc, def, g. An example is provided for 1001. Provide the most simplified expression for each output ab, cde, f, g. Use K-maps. Note: It is safe to assume that the codes 1010 to 1111 will not be produced by the numeric keypad.
2
3
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y
4
5
6 8
Value MZAX
0000 0 0 0 1 0 1 0 1 0 0 0 1 0 1
0: 2 01234 1 0 0 8 9. 1 0 1 1 1 0 5 6 0 8 9 10 0 11 1 111 111 1 FIGURE 3.29. Problem 3.12: Numpad and relationship between keys and 4-bit outputs. Complete the truth table for the circuit. - Source: Daniel Lamocca