Direct transaction mode for peripheral devices

摘要

A method and system for more directly reading from or writing to a peripheral device coupled to a computer via a standard communication protocol (such as Universal Serial Bus (USB)) by bypassing portions of the standard communication technology. The host controller monitors the status of a direct command queue after the completion of each standard communication transaction. If a command is present in the direct command queue, the command is carried out before any standard communication transactions are performed. If no command is present in the direct command queue, a standard communication transaction is carried out. The relatively long latency encountered when accessing critical command status registers via standard communication technology is thus avoided.