Equipment are needed to stick to a protocol so the interrupt-ask for (IRQ) lines is usually shared. The PCI bus involves 4 interrupt traces, INTA# via INTD#, all of which can be obtained to every unit. Nearly eight PCI gadgets share the same IRQ line (INTINA# by means of INTINH#) https://nathanlabsadvisory.com/eu-us-privacy-shield-gdpr/