Patent EP-0281325-A1 (EP)
Inventor: CROHN DAVID CHARLES
IPC: G06F15/16
Filed: 1988-02-25
Abstract: An interrupt notice system permitting individual ones of a plurality of operating devices (10) provided in a cooperative arrangement thereof, to indicate to others in that arrangement that procedures to interrupt operations of such others are being initiated, comprises signal terminals (11) to each of which a corresponding one of the operating devices (10) can be electrically connected, and with each of the signal terminals being capable of receiving signals at a receive input (13) thereof for indicating to any operating device corresponding thereto that another operating device (10), if any, is initiating procedures to interrupt operation of that corresponding operating device. Each of the signal terminals is capable of transmitting signals at a transmit output (15) thereof from any operating device corresponding thereto for being conveyed to others of the signal terminals indicating that procedures are being initiated to interrupt operations of each operating device corresponding thereto, if any. A signal controller (16) has a plurality of inputs (17) at each of which one of the signal terminals (11) is electrically connected at its transmit output (15), and having outputs (19) at each of which one of the signal terminals (11) is electrically connected at its receive input (13). The signal controller (16) is capable of providing response signals at successive ones of the signal controller outputs (18), thereby forming a first output sequence of successive output response signals, with there being one of the output response signals provided at each signal   controller output for each corresponding assignment state taken by signal controller (16), thereby forming a corresponding first state sequence of successive assignment state, where such a first output sequence of response signals occurs if signals are present on a selected one of the signal controller inputs sufficiently preceding each assignment state occurring in the first state sequence to permit that corresponding output response signal to occur. A synchronisation generator (50) has a plurality of outputs (52) at each of which one of signal terminals (11) is electrically connected at an indication input thereof. The synchronisation generator (50) is capable of providing a receive indication to each signal terminal during a corresponding one of the assignment states taken by the signal controller (16) in the first state sequence indicating that each, after receiving its receive indication, is to be ready to receive in a subsequent assignment state an output response signal from its corresponding signal controller output which occurs, if it occurs at all, in response to a signal selectively transmitted by a first selected signal terminal to its corresponding signal controller input, and being capable of providing a further transmit indication to each signal terminal during a corresponding one of the assignment states taken by the signal controller in the first state sequence indicating that each, after receiving its transmit indication, can selectively transmit a signal to its corresponding signal controller input which will result in the signal controller providing signals to a second selected signal terminal in a subsequent assignment state.