Units Are needed to comply with a protocol so which the interrupt-request (IRQ) traces may be shared. The PCI bus features four interrupt strains, INTA# by means of INTD#, all of which are offered to each device. As many as 8 PCI units share the identical IRQ line (INTINA# as https://nathanlabsadvisory.com/key-components-of-a-successful-incident-response-strategy/