Patent ID: 7620748
Filing Date: 2009-11-17
Classification: G06F

Abstract:
1. A data transfer method comprising the steps of: checking a data structure for an entry comprising a state set to be free; assigning an index of the entry to a first data descriptor and a second data descriptor whereby a data buffer is accessed by a first and second DMA engine according to the first and second data descriptor for dual channel DMA data transfer without CPU intervention subsequent to the first and second data descriptor being prepared by CPU; assigning a value to a threshold of the entry; setting the state to be ready upon assigning the threshold; preparing the first data descriptor and the second data descriptor by one or more CPU; transferring data from a source device to a data buffer using a first DMA engine according to the first data descriptor subsequent to the preparation completion thereof; setting the state to be active upon the first DMA engine starting data transfer; setting the state to be completed upon the first DMA engine data transfer reaching the threshold of the entry; transferring data from the data buffer to a destination device using a second DMA engine according to the second data descriptor upon the preparation completion thereof and the state being assigned to be completed; and setting the state to be free subsequent to the second DMA engine starting data transfer.