Products are required to adhere to a protocol so that the interrupt-request (IRQ) traces may be shared. The PCI bus includes four interrupt strains, INTA# by means of INTD#, all of which are available to every unit. Nearly 8 PCI gadgets share the same IRQ line (INTINA# by way of https://nathanlabsadvisory.com/3rd-party-security-audit-assessment/