ALLEGRO PCB SI L, XL ALLEGRO PCB PI OPTION XL Cadence Allegro PCB SI offers an integrated high-speed design and analysis environment to streamline the creation of high-speed digital printed circuit board (PCB) systems. Its advanced capabilities make it easy for electrical engineers to explore, optimize, and resolve electrical performance-related issues at all stages of the design cycle. A constraint-driven design flow increases the likelihood of first- time success and reduces overall product cost.