A seven segment display decoder takes a 4-bit input, D3:0, and produces a 7-bit output to have the LEDS display decimal digit from 0 to 9. The segments are labled as a through g. That is, Sa - Sg as shown in Figure 5. Write the truth table for the output, Sf, and use a K-map to find the simplest Boolean equation for the output. 7-segment display 4D decoder s Figure 5 D3.0 Sf. D10 0000 D3:2 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 Sf 1100 1101 1110 1111

1. Gray code to Binary converter: Gray code is one of the codes used in digital systems. It has the advantage over binary numbers that only one bit in the code word changes when going from one number to the next. (See Table 1). Design a combinational circuit with 4 inputs and 4 outputs that converts a four- bit gray code number into an equivalent four-bit Binary number. Use Karnaugh map technique for simplification. Use LogicWorks for pre-lab demonstrations. Select the library "7400dev.clf* in the Parts Palette and then select the XOR chip 74-86. This would give you a set of 4 XOR's as shown in Fig. 1, just like the hardware chip 74-86. You could use as many as needed from these XOR gates in your design. Get back to ALL LIBRARIES and select switches for the inputs and Binary Probes as indicators of the outputs. Verify your design in the pre-Lab. During the Lab construct the circuit and verify its operations.

The numbers from 0-9 and a no characters is the Basic 1 digit seven segment display * .can show False True In a (CA) method of 7 segments, the anodes of all the LED segments are * "connected to the logic "O False True Some times may run out of pins on your Arduino board and need to not extend it * .with shift registers True False

Construct the logic for 4-bit binary adder-subtractor using 4-bit parallel adder and XOR gates, draw the logic diagram, construct the circuit on hardware and complete the truth table