8-Port asynchronous adapters interrupt logic description

The interrupt logic is divided into interrupt generation logic and interrupt arbitration logic.

Both logic sections are implemented on every 8-port adapter. The interrupt generation logic provides the interface to the system. This logic generates the system interrupt requests and contains the interrupt-sharing circuitry.

The function of the interrupt arbitration logic is to identify the 8-port adapter with the highest priority interrupt pending. The logic then places the interrupt information for the highest priority port in the Interrupt Arbitration register. This is accomplished in one read operation.

The interrupt arbitration logic is unique to the 8-port adapter and should not be confused with the Micro Channel arbitration logic.