Design and Implementation of Hexadecimal Keypad Interface

This paper presents the design and implementation of a hexadecimal keypad interface on the FPGA board named as Nexys 4 DDR with Artix 7 and with Xilinx part XC7A100T-CSG324 using Verilog code. The proposed system permits real-time key detection, encoding, and display the key pressed on a 7-segment display of the FPGA board. The design consists of multiple functional modules, including a keypad scanning and an encoding the logic that converts the key press into a hexadecimal value. The system is executed using Verilog code and synthesized using Xilinx Vivado to ensure optimized resource utilization.The hardware implementation is tested through both simulation and real-time experimentation on the FPGA board. The results bespeak stable and accurate key detection, with minimal delay and error. This work provides an efficient approach for integrating a hexadecimal keypad into FPGA-based applications, which can be extended to various domains such as digital controllers, security systems, and many more. The proposed system enhances user interaction in FPGA-based designs and serves as a foundation for future research in input device interfacing.