Products are required to abide by a protocol so that the interrupt-ask for (IRQ) traces is often shared. The PCI bus contains 4 interrupt traces, INTA# by means of INTD#, all of which are offered to each unit. Around 8 PCI products share the exact same IRQ line (INTINA# by https://nathanlabsadvisory.com/ce-marking-services-european-notified-body/