Units Are required to observe a protocol so that the interrupt-request (IRQ) lines is often shared. The PCI bus contains 4 interrupt strains, INTA# by means of INTD#, all of which are available to every product. As many as 8 PCI units share the identical IRQ line (INTINA# through INTINH#) https://nathanlabsadvisory.com/certified-data-privacy-professional-cdpp/