Patent ID: 7165125

Claim:
An SATA (Serial AT Attachment) host controller capable of performing host-to-device and device-to-host communications, the host controller being operable in a PIO (Programmed I/O) data transfer mode and a DMA (Direct Memory Access) data transfer mode, the host controller comprising: a buffer unit for buffering data; and a data stream selection unit for selecting a data stream for submission to said buffer unit, wherein the data stream selection unit is connected to receive at any one time at least one of a host-to-device data stream in the PIO data transfer mode, a host-to-device data stream in the DMA data transfer mode, a device-to-host data stream in the PIO data transfer mode, and a device-to-host data stream in the DMA data transfer mode, and select from said received data streams the data stream to be submitted to said buffer unit.