FPGA Implementation of Spread Spectrum Clock Generator with Onion Modulation | A Spread Spectrum Clock Generator (SSCG) is used in electronics to purposefully vary the frequency of a clock signal via modulation. Modulation is accomplished by dispersing the energy of the signal throughout a spectrum of frequencies rather than focusing it on a certain frequency. The main objective of using the spread spectrum approach in clock generation is to minimize electromagnetic interference (EMI) and enhance electromagnetic compatibility (EMC) in electronic systems. The main reason for using many layers of modulation in spread spectrum clock production, regardless of whether the name "Onion Modulation" is used, is to provide a more advanced and adaptable method for reducing electromagnetic interference. The primary design feature of the onion wave is that the core portion of the waveform has the least steep slope, which serves to generate the output. In order to optimize the frequency effect design, the conventional approach involves using a memory ROM to regulate the slope and obtain the desired onion waveform. This current methodology necessitates substantial memory allocation and an intricate architecture, resulting in higher power consumption. The proposed method presents a unique architecture for onion modulation, which offers reduced logic size and power usage. This architecture was created using Verilog HDL, tested using Modelsim, and implemented using the Xilinx Vertex-5 FPGA.