Via-Programmable Expanded Universal Logic Gate in MCML for Structured ASIC Applications: Circuit Design

This paper presents a via-programmable expanded universal logic gate in MOS current-mode logic which can implement any 3-input Boolean function, and a significant subset of 4-input and 5-input functions. The universal logic gate is programmed with the first via mask, while metal3 and higher levels are used for cell-to-cell interconnections. Thus the cell is suitable for a structured ASIC design methodology. The circuit was used to create a functional cell library which can implement a wide range of functions. The cells are simulated to characterize delays, and a design strategy is proposed for large scale integration.