Patent ID: 6418489
Filing Date: 2002-07-09
Classification: G06F

Abstract:
In a data processing system having a processor, a memory and a direct memory access controller, the direct memory access controller having a plurality of execution units, the direct memory access controller adapted to directly execute FOR tasks assigned by the processor, method for controlling the direct memory access controller, comprising the steps of:saving context information for a task, comprising: storing a loop nest pointer value from a loop nest pointer register to a first memory location, the loop nest pointer value corresponding to a last loop control descriptor at a predetermined nest level; storing a current pointer value from a current pointer register to a second memory location, the current pointer value corresponding to a next data routing descriptor to be executed on restoration of the task; and storing context information for at least one execution unit to a third memory location; and restoring the context information for the task, comprising: determining if the at least one execution unit context information has changed; if the at least one execution unit context information has changed, writing the stored context information from the third memory location to at least one register in the at least one execution unit; writing the stored loop nest pointer value from the first memory location to the loop nest pointer register; and writing the stored current pointer value from the second memory location to the current pointer register.