Devices are necessary to stick to a protocol so which the interrupt-request (IRQ) strains might be shared. The PCI bus incorporates four interrupt traces, INTA# through INTD#, all of which are offered to each product. Around 8 PCI gadgets share a similar IRQ line (INTINA# by way of INTINH#) in https://nathanlabsadvisory.com/pci-dss/