{"id":32005,"date":"2025-09-24T10:10:34","date_gmt":"2025-09-24T17:10:34","guid":{"rendered":"https:\/\/digilent.com\/blog\/?p=32005"},"modified":"2025-10-15T13:09:16","modified_gmt":"2025-10-15T20:09:16","slug":"what-is-a-7-segment-display-and-how-does-it-work","status":"publish","type":"post","link":"https:\/\/digilent.com\/blog\/what-is-a-7-segment-display-and-how-does-it-work\/","title":{"rendered":"What Is a 7-Segment Display and How Does It Work?"},"content":{"rendered":"

Seven-segment displays are a classic tool in digital electronics, used to show numerical data in everything from clocks to calculators. At <\/span>Digilent<\/span><\/b>, we like to integrate these displays into our education-focused FPGA development boards, including the <\/span>Nexys A7<\/span><\/b><\/a> and <\/span>Basys 3<\/a>. <\/span><\/b>These displays are relatively simple to use but designing a controller for one is still complex enough to require students to build some understanding and knowledge. This makes them <\/span>ideal for both learning and teaching digital design.<\/span>\u00a0<\/span><\/p>\n

What is an LED?<\/span><\/b>\u00a0<\/span><\/h4>\n

Light-emitting diodes are one of the most foundational circuit components out there. Simply put, they have <\/span>anode<\/span><\/i> and <\/span>cathode <\/span><\/i>pins, and when a high enough voltage differential is applied across those pins, the diode emits light. For the purposes of simple digital logic, most of what you need to know is: as long as the anode has a logic \u201chigh\u201d voltage applied to it, and the cathode is grounded or at a logic \u201clow\u201d, the LED will visibly glow.\u00a0<\/span>\u00a0<\/span><\/p>\n

What Is a 7-Segment Display?<\/span><\/b>\u00a0<\/span><\/h4>\n

A 7-segment display consists of seven LEDs arranged in a figure-eight pattern. Each segment is labeled A through G, and when illuminated in specific combinations, they form digits (0\u20139) and letters (A\u2013F). Some displays also include an eighth segment for the decimal point (DP).<\/span>\u00a0<\/span><\/p>\n

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Displays often include multiple digits to represent numbers larger than the standard zero through nine a single digit offers. Seven or eight pins per digit is a lot of wires to connect to a controller chip with a potentially limited number of I\/O pins, like the FPGAs used on these boards, so, some clever tricks are used to reduce the pin count. To introduce some additional terminology:<\/span>\u00a0<\/span><\/p>\n