ABSTRACT
The history of the fi eld-programmable gate array (FPGA) dates back to the 1970s with the commercial development of programmable logic array (PLA) and programmable array logic (PAL) devices. While PLA and PAL devices have evolved into today’s complex programmable logic devices (CPLD), FPGA development took a slightly different route more akin to gate array technology. The fi rst commercially successful FPGA, the Xilinx XC2064 [1], was developed by Ross Freeman and Bernard Vonderschmitt in 1985. This device, called a logic cell array, consisted of three different types of user confi gurable elements: confi gurable logic blocks (CLB), confi gurable I/O blocks (IOB), and programmable interconnect. The schematic layout of the XC2064 logic cell array and the CLB structure is shown in Figure 3.1. The confi guration of these elements was achieved by writing data to the confi guration memory to establish the various logic functions and connections. However, it was not until 1989 when Stan Baker of EETimes came up with the term FPGA that these devices became known as fi eld-programmable gate arrays or FPGAs.
