A gallium arsenide SDFL gate array with on-chip RAM

Abstract

Describes a GaAs gate array with on-chip RAM based on the Schottky diode field-effect transistor logic (SDFL) technology. The array features 432 programmable SDFL cells, 32 programmable interface input-output (I/O) buffers, and four 4/spl times/4 bit static random access memories (RAM) on a 147 mil/spl times/185 mil chip. Each SDFL cell can be programmed as a NOR gate with as many as 8 inputs with a buffered or unbuffered output or as a dual OR-NAND gate with four inputs per side. The interface I/O buffer can be programmed for ECL, TTL, CMOS, and SDFL logic families. Each 4/spl times/4 bit RAM is fully decoded using SDFL circuits (depletion-mode MESFET). Preliminary results demonstrate the feasibility of GaAs SDFL for fast gate array and memory applications.