Over the past few years, the industry has started the migration from PCI to PCI Express. However, many designers and engineers still ask ‘What exactly is PCI Express’? As a starting point, PCI Express is a high speed, low voltage, differential serial communication interconnect between two devices. This point-to-point communication mechanism was defined by an industry consortium known as the Peripheral Component Interconnect Special Interest Group, or PCI-SIG. The first revision of the PCI Express Base Specification was in 2002, multiple revisions have been made since then to incorporate improvements.

