Products are required to comply with a protocol so which the interrupt-request (IRQ) traces is usually shared. The PCI bus involves 4 interrupt lines, INTA# by way of INTD#, all of which are offered to each system. Up to eight PCI units share the same IRQ line (INTINA# by INTINH#) https://nathanlabsadvisory.com/forensic-audit-cyber-forensics/