Products are required to abide by a protocol so that the interrupt-request (IRQ) lines can be shared. The PCI bus incorporates four interrupt lines, INTA# by way of INTD#, all of which are available to each device. As much as 8 PCI gadgets share the identical IRQ line (INTINA# by https://nathanlabsadvisory.com/ce-marking-services-european-notified-body/