Task1: BCD-to-Seven segment display:

Numbers can be represented in the pure binary system and manipulated arithmetically in much the same way as the decimal system. Though this is ideal for computing systems, the human user still likes to think and communicate in the decimal system. Furthermore, there is a need to transmit and process data for basic communication purposes as well as for numerical computation. Therefore, there is a need to code numbers and alphabetical characters in terms of binary symbols or bits. shows some of the binary codes for the decimal numbers 0 through 9. Each coding scheme has specific characteristics that makes it useful for certain applications.

Seven-Segment Display: A seven-segment indicator is used for displaying any one of the decimal digits 0 through 9. Usually, the decimal digit is available in BCD (Binary Coded Decimal). A BCD-to-seven-segment decoder circuit accepts a decimal digit in BCD and generates the corresponding seven-segment code. Figure 1 shows a diagram of a seven-segment display.

The 7447 chip is a BCD-to-seven-segment decoder/driver that converts a 4-bit BCD digit to a seven-segment code. The outputs are applied to the inputs of the seven-segment display which contains the seven LED (light-emitting diode) segments on top of the package. Since we are not using any discrete chip, you will find that we will implement the same circuit using Verilog codes to express the Boolean expression that the same decoder is using. Figure 3 shows the structure of the 7 segment display in Nexys 4 FPGA. As you can see, it is a common Anode type. So, you need to enable the 7 segment that you will be using only and disable the rest. Then send the number you want to display by controlling the 7 segment cathodes. (Note: Nexys 4 DDR has different pin names).

1. Set up the truth table (table 2 below) for the circuit shown in Error: Reference source not found, with (W X Y Z) as inputs and (A B C D E F G) as outputs.

2. Find the simplest Boolean expression for each segment from the table above and summarize them in table 3 below.

3. Write a Verilog code for a circuit that will perform the function of the BCD-7segment display. You will have 4 inputs to represent BCD number and 7 outputs to control the 7 segments cathodes. Dont forget to enable the anode of the 7 segment that you will use and disable the rest.