Devices are necessary to stick to a protocol so which the interrupt-ask for (IRQ) strains could be shared. The PCI bus consists of four interrupt lines, INTA# by INTD#, all of which are available to every device. Up to 8 PCI equipment share exactly the same IRQ line (INTINA# by https://nathanlabsadvisory.com/how-soc-2-compliance-protects-your-usa-business-from-cyber-attacks/