Devices are needed to abide by a protocol so which the interrupt-ask for (IRQ) lines could be shared. The PCI bus incorporates 4 interrupt traces, INTA# via INTD#, all of which can be found to each gadget. Around eight PCI equipment share the same IRQ line (INTINA# through INTINH#) in https://nathanlabsadvisory.com/smart-contract-audit-copyright-companies-1/