Devices are necessary to comply with a protocol so that the interrupt-request (IRQ) traces could be shared. The PCI bus involves four interrupt lines, INTA# via INTD#, all of which are available to every unit. Around 8 PCI products share precisely the same IRQ line (INTINA# via INTINH#) in APIC-enabled https://nathanlabsadvisory.com/sama-compliance-saudi-arabia/