3. Programmable circuits

These are standard components that can be electrically programmed once (fuses) or several times (reconfigurable).

• Principles

  The architectures of these circuits offer a set of logic resources (gates, flip-flops, etc.) that can be interconnected in different ways: realization of Boolean functions in the form of a limited sum of monomials (PAL, PLD circuits), or an array of cells (FPGA). Manufacturing technologies are numerous: metal fuses for the first programmable circuits based on bipolar technologies, antifuses (capacitors), floating-gate MOS transistors (EPLD), static RAM (FPGA-SRAM) or flash memory. There are three categories: