Compaq Computer Corporation, Inc.

Hewlett-packard Development Company, L.p.

Gregory N Santos

Phillip M Jones

Ronald Timothy Horan

Robert A Lester

Robert C Elliott

David J Maguire

James R Edwards

Dwight D Riley

Ronald P Meyers, Jr

Jeffrey C Tang

Gary J Piccirillo

Michael J Collins

Jerome J Johnson

William C Hallowell

Maria L Melo

Robert C Elliot

A portable computer can be 'hot' docked to one or more expansion devices, such as a drive wedge and a port replicator. As such, the expansion devices can be connected to and disconnected from the portable computer while portable computer is powered on and fully operational. The portable computer includes control logic that detects when an expansion device is connected to or disconnected from the portable computer and asserts an SMI or equivalent interrupt signal to the computer's CPU to initiate a sequence of events by which the computer determines whether an expansion device has been connected or disconnected. If the CPU determines that the expansion device has been connected to the computer, the CPU appropriately reconfigures itself to communicate with the expansion device. If the expansion device is disconnected, the CPU also appropriately reconfigures itself to preclude communications with the disconnected device.

Hot docking drive wedge and port replicator

A portable computer can be &ldquo;hot&rdquo; docked to one or more expansion devices, such as a drive wedge and a port replicator. As such, the expansion devices can be connected to and disconnected from the portable computer while portable computer is powered on and fully operational. The portable computer includes control logic that detects when an expansion device is connected to or disconnected from the portable computer and asserts an SMI or equivalent interrupt signal to the computer's CPU to initiate a sequence of events by which the computer determines whether an expansion device has been connected or disconnected. If the CPU determines that the expansion device has been connected to the computer, the CPU appropriately reconfigures itself to communicate with the expansion device. If the expansion device is disconnected, the CPU also appropriately reconfigures itself to preclude communications with the disconnected device.

A computer system having a core logic chipset that interconnects a processor(s), a system memory and peripheral device agents. The core logic chipset has a programmable memory access arbiter that may be programmed to optimize accesses by the computer system processor(s) and agents to the system memory for best computer system performance. The memory access arbiter may be programmed specifically for each system agent. An access count register may be incorporated into the core logic chipset wherein each system agent may be represented by a portion of the access count register. The values programmed into the portions of the access count register determine how many memory accesses the associated agent may take before another agent is granted a memory access, and how many cachelines may be transferred during a memory access.

Accelerated graphics port programmable memory access arbiter

A computer is provided having a bus interface unit which is coupled between a peripheral bus and a dedicated graphics bus. The graphics bus can be linked to the bus interface unit by an AGP, while the peripheral bus can be linked to the bus interface unit by a PCI. Arbitration for the AGP bus can determine when mastership is granted to an AGP master (i.e., graphics accelerator/controller). Until mastership is granted, the AGP target is powered down to a low power state where power consumption within the bus interface unit is minimal. It is not until the AGP master achieves mastership that the graphics target (core logic and memory controller) within the bus interface unit is placed in an operational (fully powered) state. The computer therefore employs a bus interface unit which can be dynamically switched from a high power state to a low power state and vice versa, depending upon accesses to the graphics target.

Device and method for reducing power consumption within an accelerated

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory. The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. The GART table is made up of a plurality of entries, each entry comprising an address pointer to a base address of a memory page, and feature flags that may be used to customize the associated memory page.

Graphics address remapping table entry feature flags for customizing the

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory. The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. Contiguous virtual memory address space must be allocated for the AGP device within the addressable memory space of the computer system, typically 4 gigabytes using 32 bit addressing. The required amount of virtual memory address space for AGP is determined from the AGP device and the information is put into a register of the core logic so that the computer system software may allocate the required amount of memory and assign a base address thereto during computer system startup or POST.

System and method for dynamically allocating accelerated graphics port

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory. The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. The GART table is made up of a plurality of entries, each entry comprising an address pointer to a base address of a page of graphics data in memory, and feature flags that may be used to customize the associated page. One of the feature flags is used as a Present Bit for a corresponding memory page. When the feature flag Present Bit is set, the memory page has been reserved in the physical memory for graphics data and an address translation may be carried out. When the feature flag Present Bit is clear, the memory page has not been reserved for graphics data in the physical memory and a determination must then be made whether to perform the translation or generate an error signal to the computer processor.

Generating an error signal when accessing an invalid memory page

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as an AGP graphics controller, and a host processor and computer system memory wherein AGP transaction read requests are merged from the AGP graphics controller and retired when these requests are within a cacheline of the memory being accessed. The core logic chipset will request a memory cacheline read as it begins processing a current AGP transaction read request. Once the memory read access is initiated, the transaction read request will be popped off an AGP request queue in order to evaluate the next in order transaction request. If the next request can be partially or completely retired by the memory read access previously started, then the memory access that would have been normally required may be skipped and the data from the previous memory read access is used instead. This AGP read transaction merging may continue until the next in order transaction read request is located in a different cacheline of memory or the original memory request is ready to return data. A memory data buffer may also be utilized to store unused quadwords of the cacheline read from a memory access so that some subsequent AGP transaction requests may be retired without having to access a previously read cacheline of memory.

Accelerated graphics port read transaction merging

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. The GART table is made up of a plurality of entries, each entry comprising an address pointer to a base address of a page of graphics data in memory. The core logic chipset may cache a subset of the most recently used GART table entries to increase AGP performance when performing the address translation. When a GART table entry is not found in the cache, a memory access is required to obtained the needed GART table entry. There are two GART table entries in each quadword returned in toggle mode of the cacheline of memory information returned from the memory read access. At least one quadword (two GART table entries) are stored in the cache each time a memory access is required because of a cache miss.

Accelerated graphics port multiple entry gart cache allocation system

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory. The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. A plurality of AGP memory-mapped status and control registers are stored in the computer system memory, and are used for status and control of AGP functions in the computer system.

Accelerated graphics port memory mapped status and control registers

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory. The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. The GART table is made up of a plurality of entries, each entry comprising an address pointer to a base address of a page of graphics data in the computer system physical memory, and feature flags that may be used to customize the associated page of graphics data. One of the feature flags is used as a link bit for each GART table entry such that when the core logic chipset reads selected ones of the GART table entries stored in the system memory, it stores a first one of the selected ones in its cache memory and determines if the link bit thereof is set. If the link bit of the first one of the selected ones is set then a next one of the selected ones is stored in the cache memory and if the link bit thereof is set then a subsequent one of the selected ones is stored in the cache memory until one of the link bits thereof is determined not to be set.

Use of a link bit to fetch entries of a graphic address remapping table

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory. The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. The GART table is made up of a plurality of entries, each entry comprising an address pointer to a base address of a page of graphics data in memory, and feature flags that may be used to customize the associated page. The core logic chipset may cache a subset of the most recently used GART table entries to increase AGP performance when performing the address translation. A GART cache entry control register is used by an application programming interface, such as a GART miniport driver, to indicate to the core logic chipset that an individual GART table entry in the chipset cache should be invalidated and/or updated. The core logic chipset may then perform the required invalidate and/or update operation on the individual GART table entry without having to flush or otherwise disturb the other still relevant GART table entries stored in the cache.

System and method for invalidating and updating individual GART table

A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ('AGP') bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ('GART table') is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory. The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. Contiguous virtual memory address space must be allocated for the AGP device within the addressable memory space of the computer system, typically 4 gigabytes using 32 bit addressing. The required amount of virtual memory address space for AGP is determined from the AGP device and the information is put into a register of the core logic so that the computer system software may allocate the required amount of memory and assign a base address thereto during computer system startup or POST. An AGP Valid bit is set to indicate whether an AGP device is present or not. If the AGP device is not present, then no virtual memory address space is allocated during the computer system startup.

Valid flag for disabling allocation of accelerated graphics port memory

A computer system having an expansion base for docking a portable portion of the computer system includes a bridge circuit for adaptively decoding addresses on a bus based on the docking status. Both the expansion base and the portable portion include the bridge circuit for passing cycles from a peripheral component interconnect (PCI) bus to an industry standard architecture (ISA) bus. The bridge includes internal devices and configuration registers for controlling the decoding. Bus cycles intended for internal devices and external devices connected to each respective ISA bus of the bridge circuits are positively decoded. Cycles not positively decoded and claimed are subtractively decoded by one of the bridge circuits depending on the docking status.

Growing community of inventors

Cypress, TX, United States of America

Gregory N Santos