Interrupt Controller Diagnostic Wrap Arrangement
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
The figure illustrates a software-generated interrupt capability that is employed to functionally test an Interrupt Controller (I.C.). This allows the system software to test the I.C. in a stand-alone environment before proceeding to test the I/O devices. This particular implementation is designed to 8 interrupt levels. However, if more than 8 or less than 8 interrupt levels are present in a system, then the Diagnostic Interrupt Register is expanded or reduced the corresponding amount. The 8 outputs of the Diagnostic Interrupt Register serve as alternate interrupt request sources. These alternate interrupt request sources are selected by the software by toggling the DIAG MODE line. If the DIAG MODE signal is on, the alternate interrupt request sources are selected.