The use of threshold functions and Boolean-controlled network elements for macromodeling of LSI circuits

The concept of threshold functions and Boolean-controlled network elements is introduced. It allows for digital macromodeling and mixing logic and timing simulation with transient analysis at device or macromodel level. A simulator for four-phase MOS LSI (4PHASE) showing a two orders of magnitude improvement in CPU time and a digital-analog simulator (DIANA) capable of mixing logic, timing, and analog simulation are shown as examples. DIANA typically allows for the simulation of an analog circuit complexity up to 50 nodes together with 400 digital macromodels on a 32K word minicomputer.