摘要:
A data communication system for communicating data between a bus running at a first clock frequency and a circuit block operating synchronously with the data bus at a second clock frequency. The system includes a clock generator for generating a bus clock signal at the first clock frequency and a chip clock signal at the second clock frequency wherein the first and second clock signal frequencies are in the ratio of (N-1):N where N is an integer greater than 1 and wherein the bus and chip clock signals are synchronized once every N cycles of the chip clock signal. The clock generator also generates a synchronization signal indicating the chip clock signal cycle in which the bus and chip clock signals are synchronized. The circuit block includes an interface circuit for receiving and transmitting data on the bus. The system also includes circuits connected to each circuit block for identifying a chip clock signal cycle in which data cannot be transmitted by the circuit block on the bus and a chip clock signal cycle in which data cannot be received by the circuit block from the bus, there being one of each type of cycle in each contiguous block of N chip clock cycles.
摘要:
A coherency scheme of use with a system having a bus, a main memory, a main memory controller for accessing main memory in response to transactions received on the bus, and a set of processor modules coupled to the bus. Each processor module has a cache memory and is capable of transmitting coherent transactions on the bus to other processor modules and to the main memory controller. Each processor module detects coherent transactions issued on the bus and performs cache coherency checks for each of the coherent transactions. Each processor module has a coherency queue for storing all transactions issued on the bus and for performing coherency checks for the transactions in first-in, first-out order. When a module transmits a coherent transaction on a bus, it places its own transaction into its own coherency queue.
摘要:
A rug or mat cleaning system is disclosed which is comprised of first a dry lint and dust removing section, then a water or like liquid containing vessel having an initial wash section and then a rinse section and then finally a wringer section. A mat to be cleaned is passed through a first conveying roller at a slower driving speed. Thereafter, the mat or rug enters an increased speed brush which both removes dirt and agitates the surface of the rug and beats it to knock loose undesireable dirt and like particles. In the wash section of the system, alternating feed rollers and brush rollers carry the mat or rug to be cleaned. Each feed roller clamps and holds the rug to prevent slipping while conveying it at a slower linear speed. Each brush roller provides a brushing surface having a substantially higher linear speed than the surface of the conveying rolls. Thus, a "tuck" or crease is created in the rug between each high speed roller brush and its adjacent and following slower conveying roll. A wringer is provided at the end of the system to remove extraneous water from the rug after its cleansing. Pressure belts are provided above the cleaning brushes for enhanced cleaning and operation. A special beater roller with projecting ridges is also included.
摘要:
An improved method of using sockets in connection with TCP over certain local networks, such as the enhanced Ethernet. In particular, an accelerated socket protocol is provided to enhance data communications between different host computer systems connected to an enhanced Ethernet network. Under the accelerated socket protocol, a host computer, while sending a number of data packets, is able to indicate a particular data packet is a last ready data packet out of all packets ready to be sent by setting a PUSH bit in that particular data packet, which triggers an automatic acknowledgement message that confirms receipt of data from the receiver. In addition, while receiving data packets, the host computer can advertise an effective window that corresponds to the actually available receiving space in the host computer.
摘要:
The use of Ethernet as an underlying transport for Fiber Channel (FC) frames is disclosed in the Fiber Channel Over Ethernet (FCOE) protocol. In FCOE, the FC physical layer and part of the FC-2 link layer are replaced with the Ethernet physical and link layers. Each FC frame is encapsulated within an Ethernet Frame. The payload of the FCOE frame contains type information from the FC Start Of Frame (SOF) indicator, the FC header, an optional FC payload, and type information from the FC End Of Frame (EOF) indicator. In one embodiment, an Ethernet network carrying FCOE replaces a standard FC network. In another embodiment, devices implementing FCOE may be implemented in a blade server. The entire backplane is Ethernet, over which both storage and networking traffic can be run. The Ethernet links are connected to an Ethernet switch, a FCOE/FC converter, and a FC switch.
摘要:
The avoidance of port collisions in a hardware-accelerated network protocol, such as Transmission Control Protocol (TCP)/Internet Protocol (IP), is disclosed. In one example, a hardware-accelerated host bus adaptor (HBA) offloads protocol processing from a host computer's operating system. However, a port collision occurs if a non-accelerated host TCP/IP stack and a hardware accelerated host bus adapter TCP/IP stack choose the same port for establishing a network connection. In a double-ended TCP/IP acceleration connection, a unique TCP port is bound to the accelerated TCP/IP stack. In a single-ended TCP/IP acceleration connection, either the host TCP/IP stack is prevented from using that port or a non-accelerated connection is associated with an accelerated connection without binding a port.
摘要:
The use of Ethernet as an underlying transport for Fibre Channel (FC) frames is disclosed in the Fibre Channel Over Ethernet (FCOE) protocol. In FCOE, the FC physical layer and part of the FC-2 link layer are replaced with the Ethernet physical and link layers. Each FC frame is encapsulated within an Ethernet Frame. The payload of the FCOE frame contains type information from the FC Start Of Frame (SOF) indicator, the FC header, an optional FC payload, and type information from the FC End Of Frame (EOF) indicator. In one embodiment, an Ethernet network carrying FCOE replaces a standard FC network. In another embodiment, devices implementing FCOE may be implemented in a blade server. The entire backplane is Ethernet, over which both storage and networking traffic can be run. The Ethernet links are connected to an Ethernet switch, a FCOE/FC converter, and a FC switch.
摘要:
A system includes a plurality of computers interconnected by a network including one or more switching nodes. The computers transfer messages over virtual circuits established thereamong. A computer, as a source computer for one or more virtual circuit(s), schedules transmission of messages on a round-robin basis as among the virtual circuits for which it is source computer. Each switching node which forms part of a path for respective virtual circuits also forwards messages for virtual circuits in a round-robin manner, and, a computer, as a destination computer for one or more virtual circuit(s), schedules processing of received messages in a round-robin manner. Round-robin transmission, forwarding and processing at the destination provides a degree of fairness in message transmission as among the virtual circuits established over the network. In addition, messages are transmitted in one or more cells, with the round-robin transmission being on a cell basis, so as to reduce delays which may occur for short messages if a long messages were transmitted in full for one virtual circuit before beginning transmission of a short message for another virtual circuit. For each virtual circuit, the destination computer and each switching node along the path for the virtual circuit can generate a virtual circuit flow control message for transmission to the source computer to temporarily limit transmission over the virtual circuit if the amount of resources being taken up by messages for the virtual circuit exceeds predetermined thresholds, further providing fairness as among the virtual circuits. In addition, each switching node or computer can generate link flow control messages for transmission to neighboring devices in the network to temporarily limit transmission thereto if the amount of resources taken up by all virtual circuits exceeds predetermined thresholds, so as to reduce the likelihood of message loss.
摘要:
A system includes a plurality of computers interconnected by a network including one or more switching nodes. The computers transfer messages over virtual circuits established thereamong. A computer, as a source computer for one or more virtual circuit(s), schedules transmission of messages on a round-robin basis as among the virtual circuits for which it is source computer. Each switching node which forms part of a path for respective virtual circuits also forwards messages for virtual circuits in a round-robin manner, and, a computer, as a destination computer for one or more virtual circuit(s), schedules processing of received messages in a round-robin manner. Round-robin transmission, forwarding and processing at the destination provides a degree of fairness in message transmission as among the virtual circuits established over the network. In addition, messages are transmitted in one or more cells, with the round-robin transmission being on a cell basis, so as to reduce delays which may occur for short messages if a long messages were transmitted in full for one virtual circuit before beginning transmission of a short message for another virtual circuit. For each virtual circuit, the destination computer and each switching node along the path for the virtual circuit can generate a virtual circuit flow control message for transmission to the source computer to temporarily limit transmission over the virtual circuit if the amount of resources being taken up by messages for the virtual circuit exceeds predetermined thresholds, further providing fairness as among the virtual circuits. In addition, each switching node or computer can generate link flow control messages for transmission to neighboring devices in the network to temporarily limit transmission thereto if the amount of resources taken up by all virtual circuits exceeds predetermined thresholds, so as to reduce the likelihood of message loss.
摘要:
A shared bus system having a bus and a set of client modules coupled to the bus. Each client module is capable of sending transactions on the bus to other client modules and receiving transactions on the bus from other client modules for processing. Each module has a queue for storing transactions received by the module for processing. A bus controller limits the types of transactions that can be sent on the bus to prevent any module's queue from overflowing.