Devices Are needed to stick to a protocol so that the interrupt-ask for (IRQ) traces may be shared. The PCI bus includes four interrupt traces, INTA# via INTD#, all of which are offered to each device. Approximately 8 PCI devices share the exact same IRQ line (INTINA# by INTINH#) in https://nathanlabsadvisory.com/rbi-cyber-security-framework/