Equipment are necessary to adhere to a protocol so which the interrupt-ask for (IRQ) lines might be shared. The PCI bus involves four interrupt strains, INTA# by way of INTD#, all of which are offered to every unit. Nearly 8 PCI units share the same IRQ line (INTINA# through INTINH#) https://nathanlabsadvisory.com/navigating-cybersecurity-and-risk-management/