| 摘要 |
A system and method using messages to access registers and memory in a PCI Express communications link environment. Vendor defined PCI Express messages can be used to read and write to the memory-mapped or register space of a device. Four types of accesses are defined using this messaging approach, namely memory read, memory write, configuration read and configuration write. The type of register access desired is defined by the appropriate value in a vendor-specific type field in the header of the vendor defined message. If a PCI Express compliant device at the other end of the PCI Express link does not support these types of messages, the messages are silently discarded by the receiver and no error is reported. |
