Equipment are needed to stick to a protocol so which the interrupt-request (IRQ) lines may be shared. The PCI bus features 4 interrupt lines, INTA# through INTD#, all of which can be found to each gadget. Up to 8 PCI devices share precisely the same IRQ line (INTINA# by INTINH#) https://nathanlabsadvisory.com/achieve-pci-dss-compliance-in-the-usa-secure-your-business-today/