System for controlling responses to requests over a data bus between a plurality of master controllers and a slave storage controller by inserting control characters

摘要

A data processing system includes one or more processors connected to a common bus, one or more I/O controllers connected to the common bus and to one or more storage subsystems and one or more storage subsystems for storing data for use in the data processing system. One or more master controllers are included in each I/O controller for communicating with a memory controller referred to as a slave which controls data flow to and from a memory subsystem. The data bus between the I/O masters and the memory controller is a multi-drop operating synchronously on a two-by-two byte parallel interface.