Conexant Systems, Inc.

Mindspeed Technologies, Inc.

Oakvale Technology

Daniel Fu

Yuanlong Wang

Earl T Cohen

Brian R Baird

Axel K Kloth

Paul Bergantino

Moshe De-Leon

Warner Andrews

Xiaofan Wei

Jeremy Bicknell

Zong Yu

Stephen M Mills

Kewei Yang

Feng Cheng Lin

Pingxi Ma

Walstein Bennett Smith, Iii

Carlton T Amdahl

Carl G Amdahl

Brian R Biard

A method and apparatus is disclosed for interfacing an asynchronous network with a synchronous network and in particular for efficiently utilizing available bandwidth of a synchronous network transmit opportunity. In one embodiment asynchronous traffic arrives via an asynchronous network at a network device, such as a switch, for transmission over a synchronous network. The traffic is parsed into cells and after switching, a reassembly unit is provided for processing one or more cells buckets. Write operations occur based on an ingress pointer while read operations are controlled by an egress pointer. Upon occurrence of a transmit opportunity on the synchronous network, the entire bandwidth of the transmit opportunity is utilized by loading awaiting cells from bucket memory on to the synchronous network. Sufficient cells are stored in memory between the memory locations identified by the ingress pointer and the egress pointer to insure total utilization of transmit opportunity bandwidth.

Pseudo synchronous machine

System and method for dynamically altering bandwidth allocation to each region serviced by a network. Each region is allocated an initial estimated bandwidth on the network and compares instantaneous demand against the allocation. When demand falls below the allocation, the region releases bandwidth so other regions can take advantage of that bandwidth. When demand exceeds the allocation, the region takes advantage of bandwidth released by other regions.

Dynamic bandwidth allocation for wide area networks

Communication circuitry is comprised of processing circuitry, parallel channels, and crossbar integrated circuits. The processing circuitry exchanges the communications between communication links and the parallel channels. The parallel channels transfer the communications in parallel with a clock signal. The crossbar integrated circuits receive the communications and the clock signal over the parallel channels, switch the communications based on the clock signal, and transfer the switched communications to the parallel channels.

Crossbar integrated circuit with parallel channels for a communication device

With directly biasing drain to source in a floating-gate N-MOSFET, a new MOSFET-fused nonvolatile ROM cell (MOFROM) is provided by tunneling-induced punch through of the drain junction to the source. The MOFROM is completely compatible with the mainstream standard CMOS process. The standard MOSFET presents an 'OFF' state before the burning and an 'ON' state with a stable low-resistance path after the burning.

MOSFET-fused nonvolatile read-only memory cell (MOFROM)

Fully connected multiple FCU-based architectures reduce requirements for Tag SRAM size and memory read latencies. A preferred embodiment of a symmetric multiprocessor system includes a switched fabric (switch matrix) for data transfers that provides multiple concurrent buses that enable greatly increased bandwidth between processors and shared memory. A high-speed point-to-point Channel couples command initiators and memory with the switch matrix and with I/O subsystems.

Fully connected cache coherent multiprocessing systems

A preferred embodiment of a symmetric multiprocessor system includes a switched fabric (switch matrix) for data transfers that provides multiple concurrent buses that enable greatly increased bandwidth between processors and shared memory. A high-speed point-to-point Channel couples command initiators and memory with the switch matrix and with I/O subsystems. Each end of a channel is connected to a Channel Interface Block (CIB). The CIB presents a logical interface to the Channel, providing a communication path to and from a CIB in another IC. CIB logic presents a similar interface between the CIB and the core-logic and between the CIB and the Channel transceivers. A channel transport protocol is is implemented in the CIB to reliably transfer data from one chip to another in the face of errors and limited buffering.

Channel interface and protocols for cache coherency in a scalable symmetric multiprocessor system

A preferred embodiment of a symmetric multiprocessor system includes a switched fabric (switch matrix) for data transfers that provides multiple concurrent buses that enable greatly increased bandwidth between processors and shared memory. A Transaction Controller, Transaction Bus, and Transaction Status Bus are used for serialization, centralized cache control, and highly pipelined address transfers. The shared Transaction Controller serializes transaction requests from Initiator devices that can include CPU/Cache modules and Peripheral Bus modules. The Transaction Bus of an illustrative embodiment is implemented using segmented buses, distributed muxes, point-to-point wiring, and supports transaction processing at a rate of one transaction per clock cycle. The Transaction Controller monitors the Transaction Bus, maintains a set of duplicate cache-tags for all CPU/Cache modules, maps addresses to Target devices, performs centralized cache control for all CPU/Cache modules, filters unnecessary Cache transactions, and routes necessary transactions to Target devices over the Transaction Status Bus. The Transaction Status Bus includes both bus-based based and point-to-point control of the target devices. A modified rotating priority scheme is used to provide Starvation-free support for Locked buses and memory resources via backoff operations. Speculative memory operations are supported to further enhance performance.

Method and apparatus for address transfers, system serialization, and centralized cache and transaction control, in a symetric multiprocessor system

The system and method for operating a cache-coherent shared-memory multiprocessing system is disclosed. The system includes a number of devices including processors, a main memory, and I/O devices. Each device is connected by means of a dedicated point-to-point connection or channel to a flow control unit (FCU). The FCU controls the exchange of data between each device in the system by providing a communication path between two devices connected to the FCU. The FCU includes a snoop signal path for processing transactions affecting cacheable memory and a network of signal paths that are used to transfer data between devices. Each signal path can operate concurrently thereby providing the system with the capability of processing multiple data transactions simultaneously.

Apparatus and method for a cache coherent shared memory multiprocessing system

A preferred embodiment of a symmetric multiprocessor system includes a switched fabric (switch matrix) for data transfers that provides multiple concurrent buses that enable greatly increased bandwidth between processors and shared memory. A Transaction Controller, Transaction Bus, and Transaction Status Bus are used for serialization, centralized cache control, and highly pipelined address transfers. The shared Transaction Controller serializes transaction requests from Initiator devices that can include CPU/Cache modules and Peripheral Bus modules. The Transaction Bus of an illustrative embodiment is implemented using segmented buses, distributed muxes, point-to-point wiring, and supports transaction processing at a rate of one transaction per clock cycle. The Transaction Controller monitors the Transaction Bus, maintains a set of duplicate cache-tags for all CPU/Cache modules, maps addresses to Target devices, performs centralized cache control for all CPU/Cache modules, filters unnecessary Cache transactions, and routes necessary transactions to Target devices over the Transaction Status Bus. The Transaction Status Bus includes both busbased and point-to-point control of the target devices. A modified rotating priority scheme is used to provide Starvation-free support for Locked buses and memory resources via backoff operations. Speculative memory operations are supported to further enhance performance.

Growing community of inventors

Saratoga, CA, United States of America

Daniel Fu