Advanced Micro Devices Corporation

Cirrus Logic Inc.

Advanced Micro Systems, Inc.

Douglas D Gephardt

James R MacDonald

Drew Jon Dutton

Dan S Mudgett

Steven L Belt

Brett B Stewart

Rita M Wisor

Scott E Swanstrom

Rodney W Schmidt

Rupaka Mahalingaiah

Andrew McBride

Kelly M Horton

Thomas Saroshan David

Qadeer Ahmad Qureshi

James David Barnette

Scott Thomas Haban

Gregory Allen North

Rita M O'Brien

James Dub Austin

Victor F Andrade

Brian Christopher Kircher

Peggy Avalos

Govinda V Kamath

A dedicated bus between a central processing unit and a peripheral unit, such as a graphics controller driving a video display, provides enhanced capability in an environment in which signal processing occurs within the central processing unit. The dedicated bus relieves other data buses, such as the PCI bus, of the need to communicate large amounts of data, such as decompressed video data. The resulting system supports high bandwidth transmissions of decompressed video data, enabling high resolution 24 bit full motion video and multiple data stream video.

Processor with decompressed video bus

A system and method for re-starting a peripheral bus clock signal and requesting mastership of a peripheral bus are provided that accommodate a power conservation technique in which a peripheral bus clock signal may be stopped. If an alternate bus master requires mastership of the peripheral bus when the peripheral bus clock signal is stopped, the alternate bus master asserts a clock request signal for re-starting the peripheral bus clock. The clock request signal is broadcasted on the peripheral bus and is accordingly received by a clock control circuit. The clock control circuit responsively causes the re-starting of the peripheral bus clock signal. Subsequently, the alternate bus master can generate a bus request signal that is synchronous to the peripheral bus clock signal to thereby obtain a grant signal from a bus arbiter unit. As a result, the peripheral bus clock signal can be stopped for power management while still accommodating alternate bus masters that must assert a synchronous bus request signal to obtain mastership of the peripheral bus.

System and method for re-starting a peripheral bus clock signal and

An audio information processing subsystem 200 is disclosed which includes a stream processor 100 for simultaneously processing multiple streams of audio data. Processing subsystem 200 also includes a program memory 202 coupled to stream processor 100 for storing instructions for controlling processing system 200 and a data memory 203/204 also coupled to stream processor 100. Additionally, a direct memory access circuitry 208 is provided for controlling direct memory accesses to a selected one of program memory 202 and data memory 203/204.

Circuits, system, and methods for processing multiple data streams

A programmable interrupt controller is provided for use in computer systems including one or more CPUs. The programmable interrupt controller includes an interrupt request interface, a storage device, and at least one processor interface having an interrupt nesting buffer. An interrupt request identification code is assigned to each interrupt request and stored in the nesting buffer. The interrupt request identification codes used to reference the interrupt requests are stored in order of their priority. Each nesting buffer need have only a number of entries equal to the number of priority levels.

Apparatus and method for storing interrupt source information in an

A data bus for connecting information processing devices is configurable into a plurality of subbusses in order to fully utilize the data bus capacity. The size and data transfer direction of each subbus, as well as the data transfer speed of each subbus, is independent of the other subbusses. Also, the data bus can be reconfigured to meet changing system requirements. A data bus controller is thus provided to accomplish this data bus reconfiguration. The reconfiguration may be accomplished in accordance with one of a plurality of information flow templates which may be stored in a memory. A method of configuring a data bus is also provided wherein information transfer needs of a system are identified and the data bus is configured according to the identified information transfer means. The reconfiguration in accordance with the information transfer needs may be accomplished in accordance with one or more information flow templates which may be stored in a memory. The system may operate in accordance with a self arbitration scheme such that reconfiguration of the system is based on operational experience, such as utilization rates or excess capacity associated with each of the subbusses.

System for dynamically reconfiguring subbusses of data bus according to

An interrupt controller includes an interrupt request register for receiving interrupt requests from various peripherals or I/O devices via a set of request lines. A priority resolver is further provided for comparing the priority level of the interrupt lines, latching the lower priority requests in a stand-by mode, and directing servicing of the highest priority level. An in-service register is provided for storing the identification of any request line that is being serviced by the microprocessor. In one embodiment, a set of signal lines are coupled between the in-service register and external terminals of the integrated circuit on which the interrupt controller is fabricated. A power management unit may be coupled to the external pins of the integrated circuit and thereby receives real-time information regarding an interrupt request that is currently being serviced and regarding interrupt service routines that have completed. Using this information, the power management unit advantageously stops unused clock signals and/or removes power from inactive circuit portions when an interrupt routine completes without having to estimate the time of completion. By accurately stopping unused clock signals and removing power, a reduction in the overall power consumption of the computer system can be attained.

Interrupt controller with external in-service indication for power

A system for effecting communications between a computing device and a plurality of peripheral devices which comprises a bus controller for controlling the communications, a plurality of feedback generator circuits for providing operational status information, each of the plurality of peripheral devices having an associated one of the plurality of feedback generator circuits. The system further comprises a bus for conveying signals between the bus controller and the plurality of peripheral devices. In the preferred embodiment, each of the plurality of peripheral devices has a respective address and each of the plurality of feedback generator circuits contains the operational status information for its respective peripheral device. The bus controller interrogates the plurality of peripheral devices, each of which causes its respective feedback generator circuit to respond to such interrogation by communicating its respective operational status information to the bus controller when a respective of the peripheral devices indicates that such information is to be passed.

System for effecting communications between a computing device and a

A symmetrical multiprocessing system is provided that includes centralized interrupt control unit. The interrupt control unit is coupled to a plurality of processing units and to a plurality of interrupt sources. The interrupt control unit advantageously allows for the expansion of each interrupt pin by setting the interrupt control unit in a cascade mode. Furthermore, the central control unit is responsive to specialized interrupt cycles which allows I/O devices and/or bus bridge devices to initiate of an interrupt without requiring a dedicated interrupt line. The central interrupt control unit further allows each interrupt to be prioritized independently of its associated vector ID, and prevents the occurrence of spurious interrupts by providing a programmable latency timer which causes the central interrupt control unit to delay its response to End Of Interrupt (EOI) instructions. An auto-chaining technique is further implemented by the central interrupt control unit to sequentially provide broadcast interrupts to various processing units based on their current task priority values. Finally, the central interrupt control unit further handles system management interrupts (SMIs) from sources such as power management units and ensures proper system operation even if the requested system management function affects operations being carried by other processing units.

Interrupt transmission via specialized bus cycle within a symmetrical

A multiprocessing computer system which includes an interrupt controller coupled to an expansion bus. The programmable interrupt controller has multiple storage locations at the same address for multiple CPUs. The CPUs are coupled to a host bus which in turn is coupled to the expansion bus by means of a bus bridge. An arbiter is coupled to the host bus for arbitrating bus mastership amongst the CPUs. CPU host owner identification for access to the storage locations is transferred across bus bridge to the programmable interrupt controller synchronized with the buffered address and data.

Multiprocessing interrupt controller on I/O bus

A non-volatile memory chip enable encoding method allows the storage of both boot code and user application software within a common memory array. The chip enable encoding method further allows a variable number of memory banks to be provided within the non-volatile memory array and allows the system to power-up and execute the boot code before the array configurations are selected by firmware. In one embodiment, a memory controller includes four chip enable output lines for selectively enabling a plurality of ROM banks. One of the ROM banks includes boot code that is executed by the system microprocessor during system boot. If the user requires a ROM array consisting of four ROM banks, a separate chip enable output line is connected to each ROM bank. If the user instead requires a ROM array consisting of, for example, eight ROM banks, an external decoder may be connected to the four chip enable output lines. In this configuration, each output line of the decoder is coupled to a respective bank enable input line of the ROM banks. In either configuration, the chip enable lines are driven in a mutually exclusive relationship during system boot to access the boot code (stored within one of the ROM banks). Subsequently, the encoding of the chip enable signals at the chip enable output lines of the memory controller is dependent upon configuration information stored in a configuration register.

ROM chip enable encoding method and computer system employing the same

Interrupt controller optimized for power management in a computer system

A method and apparatus for transferring original data which includes images, between two stations located a distance apart, without actual transmission of the image portion of the data. A library of images are provided at each of the stations. The image to be transferred is processed into a description of the image which allows the reproduction of the image at the receiving end of the transmission using the images contained in the image library in the receiving station.

System for reproducing images utilizing image libraries

A method of allocating bandwidth among a plurality of devices communicatively connected through a data bus provides for determining a data need of at least one of the plurality of devices, allocating portions of the data bus to the devices in response to the data need, and transmitting data between the devices on the allocated portions of the data bus. The portions of the data bus can be subbusses, each comprising at least one bit line. The data need can be based on a measure of fullness of a buffer corresponding to the at least one device. The data need can be provided as feedback from the buffer to a data bus controller which allocates the portions of the data bus. The method can use rules for assigning the subbusses which are stored in a memory. A processor can change the rules to accommodate changing conditions in the data bus. Also provided is a data communication system comprising a dynamically reconfigurable data bus, a data bus controller connected to the dynamically reconfigurable data bus for configuring subbusses of the data bus, a plurality of receiving devices connected to the data bus, and a feedback connection from at least one of the receiving devices to the data bus controller, wherein the data bus controller configures the subbusses in accordance with feedback received over the feedback connection. A memory can be connected to the data bus controller for storing rules for use by the data bus controller in configuring the subbusses. A processor can change the rules to accommodate changing conditions in the data bus.

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Austin, TX, United States of America

Douglas D Gephardt