1.The target must enable interrupts to receive an IRQ to its interrupt controller. This is done using the Mask register.
2.The target IRQ handler reads its status (ISR) and mask (IMR) registers to determine the identity of the initiator.
3.The target reads the Request Message written by the initiator. It processes it and provides a Response Message. The messages are in a pre-determined format in a pre-determined place in memory.
4.The target clears the IRQ in the IPI and optionally sends an IPI response to the target.