\n"); } else { $mime_type = "text/html"; header("Content-type: $mime_type; charset=utf-8"); } ?> Using Seven-Segment Displays

Directions

Seven segment displays are ubiquitous, so you are familiar with them even if you didn’t know that was what they are called. The DE1 has four of them, and we are going to use all four of them for this assignment. Each display digit can show any of sixteen characters by lighting up different combinations of the seven segments:

_ _ _ _ _ _ _ _ _ _ _ _ | | | _| _| |_| |_ |_ | |_| |_| |_| |_ | _| |_ |_ |_| | |_ _| | _| |_| | |_| | | | |_| |_ |_| |_ |

These sixteen characters, of course, are a perfect match for displaying hexadecimal digits. The Verilog module I am supplying accepts a 4-bit binary number as its input, and outputs the correct settings for the seven segments to display the corresponding hexadecimal digit.

Download hex2sevenseg.v into a Quartus project directory, add the file to the project, and create a symbol for it, just as if it was a block diagram file. This will cause the code to be compiled: make sure there are no mistakes in the process. The symbol will have a four-wire input named Hex[3..0], and a seven-wire output named Segments[6..0]. The conventional way to name the segments of a seven-segment display is with the letters A—G (or a—g), like this:

A F B G E C D

The Segments subscripts 0—6 correspond to segment letters A—G, in that order.