Products are required to observe a protocol so that the interrupt-request (IRQ) strains could be shared. The PCI bus includes four interrupt traces, INTA# via INTD#, all of which can be obtained to every unit. Nearly eight PCI products share exactly the same IRQ line (INTINA# by INTINH#) in APIC-enabled https://nathanlabsadvisory.com/security-program-advisory/