PCI-Express communications system

A PCI-Express communications method, which uses a PCI-Express switch carrying out packet transfer by connecting a plurality of modules, comprising:

• setting a unique node ID to each of a plurality of the modules for indicating every module, as well as setting a channel ID to each channel used for data transfer;
• setting in an address field of a packet for data transfer, the node ID of a transfer destination module, the channel ID of the channel used for the data transfer, and packet type to indicate a request or a response type packet;
• responding with a response packet when the packet type is a request;
• and
• using a memory write request packet to be routed according to PCI-Express switch address routing for the data transfer.

A module of a PCI-Express communication system, which uses a PCI-Express switch carrying out packet transfer, comprising:

• setting a unique node ID identifying it from a plurality of the modules of the system, as well as setting a channel ID to each channel used for data transfer;
• setting in an address field of a packet for data transfer, the node ID of a transfer destination module, the channel ID of the channel used for the data transfer, and packet type indicating a request or a response type packet;
• and
• using a memory write request packet to be routed according to PCI-Express switch address routing for the data transfer.