A 16-BIT MICROPROCESSOR HAVING HIGH THROUGHPUT AND HIGH COMPILED CODE DENSITY IS PRESENTED. ITS LANGUAGE-DIRECTED STACKARCHITECTURE, WITH THE PERFORMANCE AND DENSITY OF TWO-MICROMETER COMPLEMENTARY MOS/SILICON-ON-SAPPHIRE (SOS) VSLI TECHNOLOGY, IS DESCRIBED. THE DISCUSSION OF ADVANCED ARCHITECTUREMICROPROCESSOR (AAMP) INSTRUCTION-SET ARCHITECTURE, MICROARCHITECTURE IMPLEMENTATION, INTERFACE, AND PERFORMANCE IS PRESENTED. AN APPENDIX - A PORTION OF THE PROGRAMMER'S REFERENCE CARD - PROVIDES AN OVERVIEW OF THE INSTRUCTION SET.