Compaq Computer Corporation, Inc.

Hewlett-packard Development Company, L.P.

Compaq Information Technologies Group, L.p.

Jeffrey C Stevens

Michael J Collins

Jens K Ramsey

Robert A Lester

Charles J Stancil

John Edward Larson

Robert C Brooks

Gary J Piccirillo

Phillip M Jones

Jerome J Johnson

Kenneth T Chin

Philip C Kelly

Dwight D Riley

Randy M Bonella

Roger E Tipley

David J Maguire

Patrick Lee Ferguson

Charles N Shaver

Jeff W Wolford

Christopher C Wanner

James R Edwards

Todd J Deschepper

Russ Wunderlich

Robert L Woods

Jeffrey T Wilson

Michael E Tubbs

Shaun V Wandler

C Kevin Coffee

Mike T Jackson

Danny Higby

Sompong Paul Olarig

Gary W Thome

Kent E Biggs

Mark A Piwonka

Michael R Durham

Nam H Nguyen

Michael P Moriarty

Robert Paul Martin

Harold Merkel

Guy E McSwain

In one example in accordance with the present disclosure, a system is described. The system includes a sensor to detect an environmental condition for a computing device in which the system is disposed. A device sensor determines a temperature within the computing device. The system also includes a controller to selectively control a fan within the computing device based on the environmental condition and the temperature.

Environmental and temperature based computing device fan adjustments

An example of an apparatus is provided. The apparatus includes a power supply to connect to a power source. The power supply is to receive and to distribute a total power from the power source. The apparatus further includes a first device to receive a first portion of the total power from the power supply. The apparatus further includes a second device to receive a second portion of the total power from the power supply. A sum of the first portion and the second portion is the total power. In addition, the apparatus includes a controller to control the second device, wherein the controller is to determine the total power demanded by the first device and the second device. The controller is to reduce the second portion of the total power and to restore the second portion of the total power.

Power management systems

An example display device includes an input module to receive a touch input that identifies a shape of an electronic device. The display device also includes a display panel. The display panel is to display first data from a computing device in a first region of the display panel. The display panel is also to, in response to a reception of the touch input, display the first data in a second region of the display panel and display second data from the electronic device in a virtual representation of the electronic device in a third region of the display panel. The third region corresponds to the shape of the electronic device. The second data is received via a connection to the computing device. The second region is smaller than the first region.

Display devices with virtual reprsentations of electronic devices

A computing system is associated with power consumption based on Power over Ethernet (PoE). Power consumption is compared to a threshold, and a signal is asserted that power consumption is to be limited based on the comparison to the threshold.

Power consumption limit associated with power over ethernet (POE) computing system

Power consumption limit associated with power over ethernet (PoE) computing system

A fan speed controller for a computer system that calculates an internal central processing unit temperature and, in response to target fan speeds communicated over a system management bus, slowly adjusts the computer system fan speed such that audible noise associated with the fan speed change is not as perceptible as would be an immediate change in fan speed.

Computer fan speed system to reduce audible perceptibility of fan speed changes

A computer system includes an adaptive memory arbiter for prioritizing memory access requests, including a self-adjusting, programmable request-priority ranking system. The memory arbiter adapts during every arbitration cycle, reducing the priority of any request which wins memory arbitration. Thus, a memory request initially holding a low priority ranking may gradually advance in priority until that request wins memory arbitration. Such a scheme prevents lower-priority devices from becoming &ldquo;memory-starved.&rdquo; Because some types of memory requests (such as refresh requests and memory reads) inherently require faster memory access than other requests (such as memory writes), the adaptive memory arbiter additionally integrates a nonadjustable priority structure into the adaptive ranking system which guarantees faster service to the most urgent requests. Also, the adaptive memory arbitration scheme introduces a flexible method of adjustable priority-weighting which permits selected devices to transact a programmable number of consecutive memory accesses without those devices losing request priority.

Computer system with adaptive memory arbitration scheme

A computer system includes a CPU, a memory device, two expansion buses, and a bridge logic unit coupling together the CPU, the memory device and the expansion buses. The CPU couples to the bridge logic unit via a CPU bus and the memory device couples to the bridge logic unit via a memory bus. The bridge logic unit generally routes bus cycle requests from one of the four buses to another of the buses while concurrently routing bus cycle requests to another pair of buses. The bridge logic unit preferably includes four interfaces, one each to the CPU, memory device and the two expansion buses. Each pair of interfaces are coupled by at least one queue; write requests are stored (or &ldquo;posted&rdquo;) in write queues and read data are stored in read queues. Because each interface can communicate concurrently with all other interfaces via the read and write queues, the possibility exists that a first interface cannot access a second interface because the second interface is busy processing read or write requests from a third interface, thus starving the first interface for access to the second interface. To remedy this starvation problem, the bridge logic unit prevents the third interface from posting additional write requests to its write queue, thereby permitting the first interface access to the second interface. Further, read cycles may be retried from one interface to allow another interface to complete its bus transactions.

Computer system employing memory controller and bridge interface permitting concurrent operation

A computer system includes a CPU and a memory device coupled by a North bridge logic unit to an expansion bus, such as a PCI bus. A South bridge logic connects to the expansion bus and couples various secondary busses and peripheral devices to the expansion bus. The South bridge logic includes internal control devices or master devices that are designed to run master cycles on the expansion bus. The master devices couple to the expansion bus through a common expansion master interface, which executes master cycles on the expansion bus on behalf of the master devices. The South bridge also includes an internal modular master expansion bus coupling the internal master devices to the common master interface. The internal modular master expansion bus permits the master devices to run master cycles to any expansion bus by understanding a standardized group of signals represented by the internal modular master expansion (IMAX) bus. The master interface then is responsible for understanding the protocol of the expansion bus and converting the IMAX master bus signals to signals compatible with the expansion bus. In addition, a dedicated target IMAX bus may also be provided for coupling internal targets within the South bridge to masters on the expansion bus through a common expansion target interface.

Computer system with bridge logic that includes an internal modular expansion bus and a common master interface for internal master devices

A computer system includes a CPU and a memory device coupled by a North bridge logic unit to an expansion bus, such as a PCI bus. A South bridge logic connects to the expansion bus and couples various secondary busses and peripheral devices to the expansion bus. The South bridge logic includes internal control devices that are targets for masters on the expansion bus. The target devices couple to the expansion bus through a common expansion target interface, which monitors and translates master cycles on the expansion bus on behalf of the target devices. The South bridge also includes an internal modular target expansion bus coupling the internal target devices to the common target interface. The internal modular target expansion bus permits the target devices to receive master cycles from any expansion bus by understanding a standardized group of signals represented by the internal modular target expansion (IMAX) bus. The target interface then is responsible for understanding the protocol of the expansion bus and converting the expansion bus signals to IMAX target bus signals. The IMAX target bus includes both an inbound bus and an outbound data bus for driving out data requested as part of a read cycle to an internal target device.

Computer system with bridge logic that includes an internal modular

A computer system having separate, yet compatible DMA controllers on a bus. Each DMA controller for controlling at least one DMA channel, each DMA controller having an independent set of registers for performing DMA operations and a configuration register for indicating channel status and designation. A DMA master for compatibly communicating with a processor and for initializing and communicating with the multiple DMA controllers.

Interfacing direct memory access devices to a non-ISA bus

A circuit for placing an external or L2 cache memory into low power mode in response to certain special cycles executed by the microprocessor. In particular, the special cycles are the stop grant acknowledge special cycle and the halt special cycle. The microprocessor executes the stop grant acknowledge special cycle in response to a request by the computer system to slow down its clock. This request is asserted by the computer system if the system has been idle for a predetermined period of time. The halt special cycle is generated by the microprocessor when a HALT instruction is executed. The stop grant acknowledge and halt special cycles place the microprocessor into a low power state. Since the microprocessor is in low power mode, the L2 cache memory is also placed into low power mode for further power conservation. The L2 cache memory is implemented either with synchronous or asynchronous static random access memories (SRAMs). To place a synchronous SRAM into low power mode, its address strobe input is asserted while its chip select input is deasserted. For an asynchronous SRAM, deasserting its chip select input causes the SRAM to transition into low power mode.

Computer system that places a cache memory into low power mode in

Circuit for placing a cache memory into low power mode in response to

A cache memory system utilizing asynchronous/synchronous burst counter circuitry which lessens the need for expensive, high speed data SRAM to achieve zero wait-state operation. The burst counter circuitry takes advantage of the fact that a read address is present on the address bus approximately one-halfway through the initial bus cycle (T1) during a burst read. Unlike synchronous prior art burst counters, burst counter circuitry according to the invention is configured to forward the address to asynchronous address decoders as soon as it is present, rather than waiting for the next rising edge of the processor clock. For accesses to the first cache line, the timing budget therefore includes the first complete clock cycle of a burst read (T2) plus an extra half-clock cycle from T1. The extra time is utilized to retrieve data from the data SRAM core for provision to the processor data bus at the end of the bus cycle T2. Subsequent accesses are controlled by the burst counter in a synchronous fashion that corresponds to a processor specific burst ordering scheme. Due in part to the interleaved nature of the data SRAM, subsequent burst accesses are allotted almost 2 full clock cycles per data access. Thus, the shortest time in which the data SRAM must respond to an access request is the initial one and one-half clock cycles. Slower and less expensive data SRAMs can therefore be used to provide a cache memory capable of zero wait state operation.

Cache memory using unique burst counter circuitry and asynchronous

Growing community of inventors

Spring, TX, United States of America

Jeffrey C Stevens