Method and apparatus for trapping unimplemented operations in input/output devices

摘要

Apparatus and a method by which the flow of commands to an input/output device may be halted when the device is unable to respond to a command decoded to its address space. The apparatus includes circuitry for ascertaining whether the input/output device is able to respond to a command decoded by the decoding circuit, a circuit for storing the data and address of a command transferred to the input/output device to which the input/output device is unable to respond, and circuitry for generating a signal to disable immediately the flow of commands to the input/output device and an interrupt to assure that the unimplemented command is handled in an expeditious manner.