Devices are necessary to follow a protocol so that the interrupt-request (IRQ) strains might be shared. The PCI bus contains 4 interrupt strains, INTA# as a result of INTD#, all of which are available to every system. Approximately eight PCI products share precisely the same IRQ line (INTINA# by way https://nathanlabsadvisory.com/nist-800-cyber-security-frame-work/