Inventors:
Robert W. Horst - Saratoga CA
William Edward Baker - Austin TX
Linda Ellen Zalzala - Austin TX
William Patterson Bunton - Austin TX
Richard W. Cutts - Georgetown TX
David J. Garcia - Los Gatos CA
John C. Krause - Georgetown TX
Stephen G. Low - Austin TX
David Paul Sonnier - Austin TX
William Joel Watson - Austin TX
Patracia L. Whiteside - Austin TX
Assignee:
Tandem Computer Incorporated - Cupertino CA
International Classification:
G06F 1100
H04L 116
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.