Communication between Devices

When two devices communicate, one assumes the initiator-mode role, and the other assumes the target-mode role.

The initiator-mode device generates the command, which requests an operation, and the target-mode device receives the command and acts. It is possible for a device to perform both roles simultaneously.

When writing a new adapter device driver, the writer must know which mode or modes must be supported to meet the requirements of the adapter and any interfaced device drivers.