Abstract: A method and apparatus for transmitting data in a node having a buffer. A first set of data is received in a buffer for transmission to a target node. The first set of data is sent to the target node. Responsive to an indication that the target node is unable to receive data, a second set of data is loaded into the buffer for transmission to another target node, while the first set of data is retained in the buffer.

Abstract: A method and apparatus in a source node for transmitting data to a target node. Responsive to a request to transmit data to the target node, a determination is made as to whether a selected period of time has passed without data transmitted from the source node being received by the target node. Responsive to detecting the selected period of time has passed without data transmitted from the source node being received by the target node, a determination is made as to whether space is available in the target node to receive the data. Responsive to a determination that space is unavailable in the target node, generating an indication that the target node is blocked is generated.

Abstract: A method and apparatus for transferring data from a host to a node through a fabric connecting the host to the node. A chip architecture is provided in which a protocol engine provides for on ship processing in transferring data such that frequent interrupts from various components within the chip may be processed without intervention from the host processor. Additionally, context managers are provided to transmit and receive data. The protocol engine creates a list of transmit activities, which is traversed by the context managers, which in turn execute the listed activity in a fashion independent from the protocol engine. In receiving data, the context managers provide a mechanism to process frames of data originating from various sources without requiring intervention from the protocol engine. When receiving data, the context managers are able to process frames from different sources, which arrive out of order.

Abstract: A method and associated apparatus for using a primary FIFO and one or more secondary FIFOs in parallel to simplify flow control and routing in packet communication operations wherein at least one FIFO (buffer) is associated with each of a plurality of receiving nodes or components within a receiving node. The present invention applies received packets simultaneously to a primary FIFO and to all associated secondary FIFOs in the receiver of a packet communications link. After receipt of a packet, the packet is removed from any secondary FIFOs which correspond to receiver nodes or components to which the packet was not routed. For all receiving nodes or components to which the packet was routed, if the packet was stored in each associated secondary FIFO without overflow, then the packet is also purged from the primary FIFO.

Abstract: A method and associated apparatus for automating the filtration and generation of information in a packetized communication system. A filtration table includes entries used in recognizing a valid packet received at a node in a communication system. A mask field in each entry is applied to appropriate fields in the packet (e.g. the ordered set as applied to Fibre Channel communication systems) to determine the validity of the packet with regard to the receiving node. Rules in a field of each entry further qualify the recognition of a received packet (e.g. ordered set) by testing the reception of the packet against other logical rules. Action fields in each record permit definition of actions to be invoked automatically (e.g. automatic adjustment of fill transmissions in Fibre Channel applications) in response to receipt and recognition of a particular packet. The set of packets recognized by the receiving node may be modified by adding, deleting, or modifying the entries in the filtration table.

Abstract: An intermediate storage register is added to the combinational logic of an accumulator and is located so that a second term may be stored in the first half of an adder array, while a first term continues the accumulation process in the second half of the array.