Devices Are needed to comply with a protocol so that the interrupt-request (IRQ) strains could be shared. The PCI bus includes 4 interrupt traces, INTA# through INTD#, all of which can be obtained to every gadget. As many as 8 PCI devices share the exact same IRQ line (INTINA# via https://nathanlabsadvisory.com/cis-center-internet-security/