Four 7-segment LED numeric displays for a 24-hour clock are shown below in Figure 4. The third LED display is inverted so that the decimal points of the second and third LED displays give the appearance of a full colon. When the clock is switched on, it displays a random time and counts time by flashing the full colon every second. When the RESET button is pressed the clock resets and displays 00:00 and resumes counting time by flashing the full colon every second. It outputs hours using first and second LED displays and outputs minutes using the third and fourth LED displays.

1.Design the decoder for the third LED display. Draw the truth table for each segment of the display. Write each segment of the display as a Boolean function. Implement the functions of the last two segments as 2-level logic circuits using NOR gates.

2. Design a 4-bit counter with synchronous LOAD and asynchronous CLEAR using JK flip-flops and NOR gates. Draw its excitation table and derive its flip-flop input equations. Draw the logic circuit of the 4-bit counter.

3. Using the MC14511-B and your design in question 1 code named MD14511-Y, design the 24-hour clock as shown in Figure 4. Assume MD14511-Y has the same number of pins as MC14511-B and the pins enable the same operations. Draw the detailed logic circuit of the 24-hour clock showing the START switch and the RESET button. Print your design on an A3 sheet. Ensure that the decimal points of the first and last LED displays are always disabled.