Digital data processing system with tripartite description-based addressing multi-level microcode control, and multi-level stacks

US4532586A · kind A · utility

Assignee

• Data General Corporation · US

Inventors

• Richard G. Bratt · Wayland, US
• Stephen I. Schleimer · San Jose, US
• Edward S. Gavrin · Weston, US
• John F. Pilat · Raleigh, US
• Steven Jeffrey Wallach · Dallas, US
• Lawrence H. Katz · Oregon City, US
• Douglas M. Wells · Chapel Hill, US
• Gerald F. Clancy · Saratoga, US
• Craig J. Mundie · Seattle, US
• David H. Bernstein · Oakland, US
• Thomas M. Jones · Houston, US
• Brett L. Bachman · Boston, US

Key dates

• Filing date: May 22, 1981
• Grant date: Jul 30, 1985
• Expiry date: May 22, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F7/49926
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A digital computer system in which data storage is referred to by a descriptor comprising an object number denoting a variable-length block of storage, an offset indicating how far into that block a desired data item begins, and a length field denoting the length of the desired data item. Separate means exist for manipulating each of the three descriptor portions, thus facilitating repetitive operations on related or contiguous operands. Various levels of microcode control are included. Each level of microcode control has its own stack, facilitating interrupts between levels. Stacks are duplicated in "secure stacks" in memory to protect against loss of state data from the stacks.