Iop/Ioa Bus Isolation During Operational Mode
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
This article describes a technique that incorporates an isolation algorithm at operational time which will isolate a failing field replaceable unit (FRU) because of input/output adapter (IOA) bus problems on the input/output processor (IOP). Typically, there is no IOA bus isolation for failures on the IOA bus during operational mode and the whole IOP subsystem is suspect. The incorporation of an isolation algorithm at operational time will isolate the failing FRU due to IOA bus problems. Fig. 1 illustrates the IOP-IOA hardware in block diagram. At operational time if there is an IOA bus error, the subsystem is at a standstill. The IOP will shutdown the IOA bus via hardware aids that degate critical interface lines so that the IOP microcode can now reeestablish communications with the system.