Products are required to adhere to a protocol so the interrupt-request (IRQ) lines is often shared. The PCI bus incorporates four interrupt lines, INTA# by INTD#, all of which are offered to every device. Around eight PCI units share the identical IRQ line (INTINA# by INTINH#) in APIC-enabled x86 devices. https://nathanlabsadvisory.com/sama-compliance-saudi-arabia/