Gadgets are required to abide by a protocol so that the interrupt-request (IRQ) lines might be shared. The PCI bus contains 4 interrupt strains, INTA# through INTD#, all of which are available to each system. As many as 8 PCI devices share the identical IRQ line (INTINA# by INTINH#) in https://nathanlabsadvisory.com/cybersecurity-technical-writing/