1. History and terminology

Compared with software-based solutions, integrated circuits can achieve very high performance with very low power consumption. This is due to the specialization of functions integrated into the circuit. On the other hand, an IC is dedicated to one task, or a small set of tasks, whereas a processor has virtually unlimited flexibility. Reconfigurable architectures, in particular FPGAs, offer, to a certain extent, compromises between flexibility, cost and performance unattainable by ASICs and processors.

Very early in the history of microelectronics, several devices were proposed to make integrated circuits more flexible through programming or configuration. Two levels of programming were proposed: direct and total programming by the user, and partial programming in the foundry.

• The first to appear were PLAs (Programmable...