Assigning IRQs to I/O devices

• The PCI bus system allows some flexibility

• Each I/O interface offers a range of port addresses and of IRQs

• The objective is to separate the I/O ports and to assign, if possible, a separate IRQ to each I/O device

• IRQ sharing is possible on the PCI bus

• Detecting which among several I/O device issued the IRQ is a task demanded to the kernel