Devices are required to observe a protocol so which the interrupt-ask for (IRQ) strains could be shared. The PCI bus features 4 interrupt lines, INTA# via INTD#, all of which can be obtained to each gadget. Approximately eight PCI devices share the identical IRQ line (INTINA# by way of INTINH#) https://nathanlabsadvisory.com/iot-testing-in-the-usa-protect-your-devices-from-cyber-threats/