Devices are required to adhere to a protocol so the interrupt-ask for (IRQ) traces could be shared. The PCI bus involves four interrupt strains, INTA# by way of INTD#, all of which can be obtained to each device. Up to 8 PCI units share the identical IRQ line (INTINA# by https://nathanlabsadvisory.com/iso-iec-19770-1-2017-it-asset-management/