Method of data communication flow control in a data processing system using busy/ready commands

US6157967A · kind A · utility

Assignee

• Tandem Computers Incorporated · US

Inventors

• Robert W. Horst · San Jose, US
• William E. Baker · Austin, US
• Linda Ellen Zalzala · Austin, US
• William P. Bunton · Pflugerville, US
• Richard W. Cutts, Jr. · Georgetown, US
• David J. Garcia · Los Gatos, US
• John C. Krause · Georgetown, US
• Stephen G. Low · Austin, US
• David P. Sonnier · Austin, US
• William J. Watson · Austin, US
• Patracia L. Whiteside · Austin, US

Key dates

• Filing date: Dec 30, 1997
• Grant date: Dec 5, 2000
• Expiry date: Dec 30, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F15/17381
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A multiprocessor system includes a number of sub-processor systems, each substantially identically constructed, and each comprising a central processing unit (CPU), and at least one I/O device, interconnected by routing apparatus that also interconnects the sub-processor systems. A CPU of any one of the sub-processor systems may communicate, through the routing elements, with any I/O device of the system, or with any CPU of the system. Communications between I/O devices and CPUs is by packetized messages. Interrupts from I/O devices are communicated from the I/O devices to the CPUs (or from one CPU to another CPU) as message packets. CPUs and I/O devices may write to, or read from, memory of a CPU of the system. Memory protection is provided by an access validation method maintained by each CPU in which CPUs and/or I/O devices are provided with a validation to read/write memory of that CPU, without which memory access is denied.