PCI Express supports three interrupt reporting mechanisms:
1. Message Signaled Interrupts (MSI)
– Legacy endpoints are required to support MSI (or MSI-X) with 32- or 64-bit MSI capability register implementation
– Native PCI Express endpoints are required to support MSI with 64-bit MSI capability register implementation
2. Message Signaled Interrupts - X (MSI-X)
– Legacy and native endpoints are required to support MSI-X (or MSI) and implement the associated MSI-X capability register
3. INTx Emulation.
– Native and Legacy endpoints are required to support Legacy INTx Emulation
– PCI Express defines in-band messages which emulate the four physical interrupt signals (INTA-INTD) routed between PCI devices and the system interrupt controller
– Forwarding support required by switches Interrupt
Partager