Intimate mixing of analogue and digital signals in a field-programmable mixed-signal array with lopsided logic

Abstract

A field-programmable device has been developed, specialised for neural signal processing and neural modelling applications. The device combines analogue and digital functions, yet unlike other designs for Field-Programmable Mixed-signal Arrays (FPMA), there is no separation between the analogue and digital domains. To allow analogue values to act directly as inputs to digital blocks, all digital circuitry has limited crowbar current. The method of limiting yields lopsided logic thresholds. Two uses of this are demonstrated: a gate which detects digital saturation, and a D-type flip flop which is insensitive to clock slew rate.