Patent ID: 6012106
Filing Date: 2000-01-04
Classification: G06F

Abstract:
A process for providing data from a memory to a peripheral device in a data processing system in response to a direct memory access (DMA) read transaction request, the process comprising the steps of:(a) determining a memory page number from a starting memory address specified in the DMA read transaction request;(b) determining a prefetch length value given a memory page number, by accessing a page table that stores a prefetch length value for each of a plurality of pages in the memory;(c) prefetching data from a number of storage locations in the memory equal to the prefetch length value;(d) providing data to the peripheral device as retrieved from the memory until the DMA read transaction request terminates;(e) counting the actual total number of storage locations retrieved during the DMA read transaction; and(f) updating the prefetch length value for the page as a function of the actual number of locations transferred during the DMA read transaction.