Patent ID: 7428600
Filing Date: 2008-09-23
Classification: H04L

Abstract:
1. A data transfer control device for data transfer over a bus, the data transfer control device comprising: transfer condition registers that store transfer condition information; a transfer controller that performs the data transfer including a control transfer, based on the transfer condition information set in the transfer condition registers; and a buffer controller that performs access control of a packet buffer that stores transfer data to be transferred over the bus, the transfer controller automatically issuing a setup stage transaction and automatically transferring a setup stage packet when a start of an automatic control transfer is instructed and the data transfer control device operates as a host, then automatically issuing a data stage transaction and automatically transferring a data stage packet when there is data to be transferred in a data stage, and then automatically issuing a status stage transaction and automatically transferring a status stage packet, a data stage present/absent information and a transfer direction in the data stage being set as the transfer condition information in the transfer condition registers, the transfer controller comprising: a selection circuit that selects one of an execution of a data stage IN transaction, an execution of a data stage OUT transaction, and a no data stage, the selection being based on the transfer direction in the data stage and the data stage present/absent information set in the transfer condition registers, and the selection occurring when the setup stage transaction has completed.