Abstract: A communications system for transmitting data utilizes one or more picoprocessors located logically out of the main data path for conducting calculations and control functions in a fashion which is decoupled or separate from the main data path. In particular, the system utilizes multiple picoprocessors for performing buffer management and high performance buffer chaining processes out of the main data path so that the main data path may be continually used in parallel. In this manner, data transfer is enhanced by offloading functions and responsibilities from the main system processor and removing unnecessary traffic from the main data path.

Abstract: The connection capability of a communication controller is extended. The communication controller includes a central control unit CCU, running a network control program NCP stored in a memory having a direct memory access facility through a DMA bus. The input/output bus of the communication controller and DMA bus are connected to line adapters, and channel adapters and a controller extension through a coupler which allows additional adapters to be connected to the controller. At initialization, a table is built into a coupler memory, which is then used in steady state mode for controlling the transmission of the messages to the additional users and the reception of the messages from the additional users, by improving the buffer unchaining and chaining processes into the NCP memory.