Units are needed to follow a protocol so that the interrupt-request (IRQ) strains could be shared. The PCI bus features 4 interrupt lines, INTA# by means of INTD#, all of which can be obtained to each product. Up to eight PCI gadgets share the exact same IRQ line (INTINA# through https://nathanlabsadvisory.com/navigating-the-2025-cybersecurity-threat-landscape/