Patent ID: 7505461
Filing Date: 2009-03-17
Classification: G06F

Abstract:
1. A data transfer control device for data transfer, the data transfer control device comprising: a hub dedicated data storage section which stores a packet transferred between the data transfer control device and a hub; a packet transmission section which cyclically issues a token packet to the hub for asking whether the state of the hub has changed or not; a packet reception section which receives a response packet sent from the hub in response to the token packet; a transfer controller which writes the response packet received by the packet reception section into the hub dedicated data storage section, and generates an interrupt which indicates that the state of the hub has changed; a packet buffer in which a plurality of pipe regions are allocated, each of the plurality of pipe regions storing a packet transferred between one of the plurality of pipe regions and a corresponding endpoint; and a transfer mode setting register in which is set data for setting a hub dedicated transfer mode or a normal transfer mode, wherein a storage region of the hub dedicated data storage section is allocated for the transfer between the data transfer control device and the hub which is the endpoint when the hub dedicated transfer mode is set in the transfer mode setting register; and wherein a storage region of the packet buffer is allocated for the transfer between the data transfer control device and the hub which is the endpoint when the normal transfer mode is set in the transfer mode setting register.