Units are needed to adhere to a protocol so the interrupt-ask for (IRQ) lines could be shared. The PCI bus incorporates four interrupt strains, INTA# via INTD#, all of which are offered to every gadget. Approximately 8 PCI devices share precisely the same IRQ line (INTINA# as a result of https://nathanlabsadvisory.com/iso-iec-19770-1-2017-it-asset-management/