A seven-segment display decoder takes a 4-bit data input D0, D1, D2, and D3, and produces seven outputs to control light-emitting diodes to display a digit from 0 to 9. The seven outputs are often called segments a through g, or Sa-Sg, as defined in Figure 1. The digits are shown in Figure 2. 7-segment display.png Figure 1 Digits.png Figure 2

(a) Derive Boolean equations for the output Sd assuming that inputs greater than 9 must produce blank (0) outputs. Hint: First derive the truth table for the inputs D0, D1, D2, and D3 and the output Sd.

(b) Draw a reasonably simple gate-level implementation of part (a). Multiple outputs can share gates where appropriate.

ILLLLILLIIL 0 3 6 7 8