Instruction execution modification mechanism for time slice controlled data processors

US4109311A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Arnold Blum
• Horst VON DER Heyden · Eppelheim, DE
• Fritz Irro
• Stephan Richter · Neubiberg, DE
• Helmut Schaal · Waldenbuch, DE
• Hermann Schulze-Schoelling

Key dates

• Filing date: Sep 23, 1976
• Grant date: Aug 22, 1978
• Expiry date: Sep 23, 1996

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F9/3851
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

An instruction execution modification mechanism is described for a digital data processor wherein multiple programs or tasks are performed in a concurrent manner by means of a time slice mechanism which causes the instructions from the different programs to be executed in an interleaved manner. Instructions from the different programs are executed during different successive time slice intervals. The instruction execution modification mechanism is responsive to the occurrences of various predetermined conditions in the data processing system for selectively modifying the normal execution of different ones of the instructions in different ones of the programs. To this end, there is provided a program list mechanism listing the modifiable programs, an instruction list mechanism listing the modifiable instructions and a modification storage mechanism for storing modification signals for the different instructions. If, during a given time slice interval, the program to be executed is on the modifiable program list and the instruction to be executed is on the modifiable instruction list and the appropriate condition is occurring in the data processing system, then the modification stora…