Abstract: One embodiment of the present invention provides a system that switches from a first graphics processor to a second graphics processor to drive a display. During operation, the system receives a request to switch a signal source which drives the display from the first graphics processor to the second graphics processor. In response to the request, the system first configures the second graphics processor so that the second graphics processor is ready to drive the display. Next, the system switches the signal source that drives the display from the first graphics processor to the second graphics processor, thereby causing the second graphics processor to drive the display.

Abstract: A method and apparatus for viewing and/or analyzing the operations and logical states of an integrated circuit. The logical state of various flip-flops within the ASIC may be determined at a specified time. The embodiment may store these flip-flop states in a computer-readable data structure, such as a file or database. By repeating this process and incrementing or decrementing the time with each repetition, a more complete picture of the ASIC's operation may be captured. Additionally, the embodiment may graphically display the flip-flop states, for example as a graph or waveform.

Abstract: A computer system includes a processor, a memory, first and second graphical processors that have different operating characteristics, a switching mechanism coupled to the graphical processors, and a display coupled to the switching mechanism. The switching mechanism is configured to couple a given graphical processor to the display, and is initially configured to couple the first graphical processor to the display. Furthermore, a program module, which is stored in the memory and configured to be executed by the processor, is configured to change a configuration of the switching mechanism thereby decoupling the first graphical processor from the display and coupling the second graphical processor to the display. Note that the changing of the configuration and switching module operations are configured to occur while an operating system is running and are based on the operating condition of the computer system.

Abstract: A method and apparatus for viewing and/or analyzing the operations and logical states of an integrated circuit. The logical state of various flip-flops within the ASIC may be determined at a specified time. The embodiment may store these flip-flop states in a computer-readable data structure, such as a file or database. By repeating this process and incrementing or decrementing the time with each repetition, a more complete picture of the ASIC's operation may be captured. Additionally, the embodiment may graphically display the flip-flop states, for example as a graph or waveform.

Abstract: One embodiment of the present invention provides a system that includes an I/O descriptor cache that is accessed by a bus mastering I/O controller. The I/O descriptor cache stores descriptors that describe data to be transferred during corresponding I/O operations. The system also includes an I/O controller configured to control one or more I/O devices. This I/O controller is configured to access I/O descriptors stored in the I/O descriptor cache without having to access the main memory, thereby conserving I/O bandwidth and power.

Abstract: A method and apparatus for viewing and/or analyzing the operations and logical states of an integrated circuit. The logical state of various flip-flops within the ASIC may be determined at a specified time. The embodiment may store these flip-flop states in a computer-readable data structure, such as a file or database. By repeating this process and incrementing or decrementing the time with each repetition, a more complete picture of the ASIC's operation may be captured. Additionally, the embodiment may graphically display the flip-flop states, for example as a graph or waveform.

Abstract: One embodiment of the present invention provides a system that switches between frame buffers which are used to refresh a display. During operation, the system refreshes the display from a first frame buffer which is located in a first memory. Upon receiving a request to switch frame buffers for the display, the system reconfigures data transfers to the display so that the display is refreshed from a second frame buffer which is located in a second memory.

Abstract: Devices are assigned to different buses at development time as well as dynamically during operation, based on actual performance. At development time, bus assignment can be determined based on experiments and direct observation of how devices behave in various configurations. At run time, load on each bus is preferably measured periodically, and when it is uneven, devices are reallocated to different buses. In an alternative embodiment, a user can specify a preference for using more or fewer buses in order to optimize operation for efficiency or lower power consumption.

Abstract: A computer system includes a processor, a memory, first and second graphical processors that have different operating characteristics, a switching mechanism coupled to the graphical processors, and a display coupled to the switching mechanism. The switching mechanism is configured to couple a given graphical processor to the display, and is initially configured to couple the first graphical processor to the display. Furthermore, a program module, which is stored in the memory and configured to be executed by the processor, is configured to change a configuration of the switching mechanism thereby decoupling the first graphical processor from the display and coupling the second graphical processor to the display. Note that the changing of the configuration and switching module operations are configured to occur while an operating system is running and are based on the operating condition of the computer system.

Abstract: One embodiment of the present invention provides a system that switches from a first graphics processor to a second graphics processor to drive a display. During operation, the system receives a request to switch a signal source which drives the display from the first graphics processor to the second graphics processor. In response to the request, the system first configures the second graphics processor so that the second graphics processor is ready to drive the display. Next, the system switches the signal source that drives the display from the first graphics processor to the second graphics processor, thereby causing the second graphics processor to drive the display.

Abstract: A controller (or controller chip) providing reduced power consumption without impacting performance is disclosed. The controller monitors activity of components within the controller which require access to a local memory, and then decreases a clocking frequency for a memory interface to the local memory when the monitoring indicates that reduced amounts of activity are present. Following such a decrease in the clocking frequency, when increased amounts of activity are detected, the clocking frequency is increased for high performance operation. The controller thus tailors the clocking frequency for the memory interface in accordance with the amount of activity of these components that require access to the local memory so that overall less power is used by the controller yet the performance is essentially not hindered. In one embodiment, the controller is a graphics controller, as such controllers require access to local memories.

Abstract: Power management approaches for computer systems having one or more processors are disclosed. One power management approach provides hierarchical power management. The hierarchical nature of the power management provided by the invention has various levels of power management such that power consumption of the computer system is dependent upon the amount of work placed on the processing resources of the computer system. Another power management approach pertains to deterministic handshaking provided between a power manager and one or more controller units. The deterministic handshaking provides for more reliable and controllable transitions between power management states which have associated power management taking place in the controller units. The power management approaches are suitable for use with a single-processor computer system or a multi-processor computer system.

Abstract: Apparatus and techniques for awakening bus circuitry from an inactive state as needed are described. The bus circuitry forms part of a computer system and is placed in the inactive state (i.e., shut down) when not needed so as to conserve power. The bus circuitry is associated with a bus and can be awakened out of the inactive state when certain bus events, including resume, connect or disconnect, occur on the bus. The invention is particularly advantageous for computing devices (e.g., portable computers, desktop computers, server computers) where it is desirous to shut down bus circuitry as well as other circuitry (e.g., microprocessor) when not needed so as to reduce power consumption.

Abstract: Methods and apparatus that provide stable clock generation within a functional integrated circuit are disclosed. The functional integrated circuit provides a function other than clock generation, such as a peripheral or interrupt control. Typically, the clock generation is phase-lock loop (PLL) based. The functional integrated circuit also typically provides power savings modes to conserve power consumption.

Abstract: Apparatus and techniques for awakening bus circuitry from an inactive state as needed are described. The bus circuitry forms part of a computer system and is placed in the inactive state (i.e., shut down) when not needed so as to conserve power. The bus circuitry is associated with a bus and can be awakened out of the inactive state when certain bus events, including resume, connect or disconnect, occur on the bus. The invention is particularly advantageous for computing devices (e.g., portable computers, desktop computers, server computers) where it is desirous to shut down bus circuitry as well as other circuitry (e.g., microprocessor) when not needed so as to reduce power consumption.

Abstract: Apparatus and techniques for awakening bus circuitry from an inactive state as needed are described. The bus circuitry forms part of a computer system and is placed in the inactive state (i.e., shut down) when not needed so as to conserve power. The bus circuitry is associated with a bus and can be awakened out of the inactive state when certain bus events, including resume, connect or disconnect, occur on the bus. The invention is particularly advantageous for computing devices (e.g., portable computers, desktop computers, server computers) where it is desirous to shut down bus circuitry as well as other circuitry (e.g., microprocessor) when not needed so as to reduce power consumption.

Abstract: A method and an apparatus for interleaving display frame buffers for use by multi-panel display(s) is disclosed. The system provides a data addressing transformation apparatus for converting CPU addresses for pixel positions of the multiple panels of display screen(s) to corresponding memory addresses so as to enable multiple video frame buffers to be interleavably stored in and retrieved from a single video memory system.

Abstract: A method and an apparatus for interleaving display frame buffers is disclosed. The system includes a processor providing CPU addresses for peripheral (access, a display system, a single memory system for storing multiple frame buffers, data buses for transferring image information and a video controller for processing the image information received and for converting CPU addresses into memory addresses for accessing the memory system. The multiple frame buffers stored in the memory system in accordance with the present invention provide either overlay images for a display or separate images for separate displays or both.

Abstract: A method and an apparatus for rotating images on a computer system is disclosed. The system includes a processor for accessing an image frame buffer using a set of CPU addresses, a memory for storing the frame buffer, a controller for directing the pixel data of the frame buffer to a display device using a set of controller addresses. The two sets of addresses are not necessarily the same. In fact, numerous advantages could be had from manipulating those two sets of addresses resulting in image rotation operations for the display device.

Abstract: A method and an apparatus for rotating images on a computer system is disclosed. The system includes a processor for accessing an image frame buffer using a set of CPU addresses, a memory for storing the frame buffer, a controller for directing the pixel data of the frame buffer to a display device using a set of controller addresses. The two sets of addresses are not necessarily the same. In fact, numerous advantages could be had from manipulating those two sets of addresses resulting in image rotation operations for the display device.