4.9 An ABCD-to-seven-segment decoder is a combinatio onal circuit that converts a decimal or used digit in BCD to an appropriate code for the selection of segments in an indicat to display the decimal digit in a familiar form. The seven outputs of the d c d, e, f. 8) select the corresponding segments in the display, as shown in Fig, P49a The numeric display chosen to represent the decimal digit is shown in Fig. P Using a truth table and Karnaugh maps, design the BCD-to-seven-segment decoder using a minimum number of gates. The six invalid combinations should result in a blank display. (HDL-see Problem 4.51.) ecoder own in Fig, P4.9(a) 4.9(b). (a) Segment designation (b) Numerical designation for display FIGURE P4.9