Patent ID: 6327271
Filing Date: 2001-12-04
Classification: H04L,H04Q

Abstract:
A receiving apparatus for partially reassembling cells of data of a protocol data unit received over an asynchronous transfer mode (ATM) network by a host computer system, the receiving apparatus comprising:an adapter memory including memory slots arranged for the storage of data;a memory location in the adapter memory holding a value for a group size parameter wherein the group size parameter is less than the number of cells in the protocol data unit;a reassembly engine circuit arranged to receive the cells of data and to allocate one of the memory slots for each received cell, each of the cells of data indicating one of a plurality of virtual circuits to which each of the cells of data corresponds, the reassembly engine circuit being further arranged to form groups of the cells of data based upon one of the virtual circuits to which the groups of the cells of data belong, each group of the cells of data having a size defined by the group size parameter; anda direct memory access (DMA) engine circuit arranged to receive the groups of the cells of data and to transfer the groups of the cells of data via a DMA transfer to a system memory of the host computer system, whereby the protocol data unit is reassembled in the system memory;wherein the memory location holding the value for the group size parameter is arranged to hold a changing value for the group size parameter such that the group size parameter is programmed in order to optimize the reassembly of the protocol data unit.