Units Are necessary to stick to a protocol so the interrupt-request (IRQ) lines might be shared. The PCI bus consists of 4 interrupt traces, INTA# by means of INTD#, all of which are available to each gadget. Nearly eight PCI devices share the identical IRQ line (INTINA# by means of https://nathanlabsadvisory.com/iso-27701-privacy-information-management-system-pims/