STORAGE OF INPUT/OUTPUT COMMAND TIMEOUT AND ACKNOWLEDGE RESPONSES

摘要

A data processing system includes a number of subsystems all coupled in common to a system bus and communicate with each other by sending and receiving commands sent over the system bus. A central processing subsystem includes a response memory for storing indication of the responses sent by the receiving subsystem when receiving commands sent by the central processing subsystem. The responses include an acknowledge response, a not acknowledge response or no response--a timeout. Storing the acknowledge response and the timeout will enable the programmer to determine which of the three responses was received.