the display module. lghted when a logic , 7, 5, and 4, and "8" by lighting all seven seg- ogic 1 is applied to the corresponding input on a FIGURE 8-15 circuit Driving Seven-Segment Seven-Segment Indicator Module Inputs From n Toggle C- | Designed X 06 A- | Circuit 2 to be gage Learning 2014 Switches 4 5 7 8.A Design an 8-4-2-1 BCD code converter to drive a seven-segment indicator. The four inputs to the converter circuit (A, B, C, and D in Figure 8-15) represent an 8-4-2-1 binary-coded-decimal digit. Assume that only input combinations representing the digits 0 through 9 can occur as inputs, so that the combinations 1010 through 1111 are don't-cares. Design your ci gates and inverters A, B, C, and D will be available from toggle switches. . rcuit using only two-, three-, and four-input NAND . Try to minimize the number of gates required. The variables Use (not for 6. Use(not ) for 9. Any solution that uses 18 or fewer gates and inverters (not counting the four invert- ers for the inputs) is acceptable. 8.B Design an excess-3 code converter to drive a seven-segment indicator. The four inputs to the converter circuit (A, B, C, and D in Figure 8-15) represent an excess-3 coded decimal digit. Assume that only input combinations representing the dig- nt the siy unused combinations are don't-