Advanced Micro Devices Corporation

Ati Technologies Ulc

Joerg Winkler

Frank Barth

Thomas Kunjan

Dale E Gulick

John Kalamatianos

Maurice B Steinman

Terry Lynn Cole

Jonathan Mercer Owen

Guhan Krishnan

Antonio Asaro

Ralf Flemming

Timothy C Maleck

Don Cherepacha

Larry David Hewitt

Paul C Miranda

Thomas R Kunjan

A hierarchical memory request stream arbitration technique merges coherent memory request streams from multiple memory request sources and arbitrates the merged coherent memory request stream with requests from a non-coherent memory request stream. In at least one embodiment of the invention, a method of generating a merged memory request stream from a plurality of memory request streams includes merging coherent memory requests into a first serial memory request stream. The method includes selecting, by a memory controller circuit, a memory request for placement in the merged memory request stream from at least the first serial memory request stream and a merged non-coherent request stream. The merged non-coherent memory request stream is based on an indicator of a previous memory request selected for placement in the merged memory request stream.

Hierarchical memory arbitration technique for disparate sources

A hierarchical memory request stream arbitration technique merges coherent memory request streams from multiple memory request sources and arbitrates the merged coherent memory request stream with requests from a non-coherent memory request stream. In at least one embodiment of the invention, a method of generating a merged memory request stream from a plurality of memory request streams includes merging coherent memory requests into a first serial memory request stream. The method includes selecting, by a memory controller circuit, a memory request for placement in the merged memory request stream from at least the first serial memory request stream and a merged non-coherent request stream. The merged non-coherent memory request stream is at least partially based on an indicator of a previous memory request selected for placement in the merged memory request stream.

An improved interface technique for use in a southbridge or I/O hub or in similar devices is provided where non-posted read requests are received from at least one requestor, and upstream commands based on these requests are transmitted. Response data is received in reply to commands that were previously transmitted, and responses are transmitted to the at least one requester based on the response data. A buffer unit is provided for storing command identification data that identifies commands that were already transmitted or that are still to be transmitted, and response availability data that specifies response data that has been received by the receive engine. The improvement may enable multiple outstanding read requests.

Buffering non-posted read commands and responses

An integrated circuit chip, particularly a southbridge, is provided that has a first and a second circuit unit. Each circuit unit can send requests to the other one and send back a response when receiving a request that requires a response. The first circuit unit is connected to the second circuit unit to send to the second circuit unit request data relating to a request to be sent by the first circuit unit and response data relating to a response to be sent by the first circuit unit over a shared signal line.

Combined command and response on-chip data interface for a computer system chipset

An interrupt processing technique is provided where an interrupt message is sent to an interrupt controller of a processor in response to an interrupt request from an individual device. The interrupt message comprises a memory address and interrupt status information. The memory address is specifically allocated to the device that has issued the interrupt request. The interrupt status information indicates an interrupt status of the device. An interrupt table that is stored in the memory is updated by the interrupt controller using the interrupt status information comprised in the interrupt message. The interrupt table holds device specific interrupt statuses. Updating the interrupt table comprises addressing the memory using the memory address in the interrupt message.

Message based interrupt table

A method an apparatus for providing capability information to a shared controller. In one embodiment, a peripheral bus host controller may be shared by a plurality of peripheral devices coupled to a peripheral bus. The peripheral devices may include coder/decoder (codec) circuitry, and may be implemented using a riser card. The host controller may be configured to query the bus for peripheral devices by reading each address on the bus. During the querying process, the host controller may detect one or more peripheral devices coupled to the bus. Following the completion of the querying of the bus, the host controller may then begin reading configuration information from each of the detected devices. The host controller may employ one or more of several different techniques in order to read configuration information from the peripheral device. The configuration information at a minimum includes a device identifier, which may identify the vendor and the function of the device. Additional information needed to configure the device to communicate over the peripheral bus may also be obtained with a read of the device, or various lookup mechanisms, such as a lookup table or a tree-like data structure. After configuration information has been obtained for each device coupled to the bus, the host controller may dynamically configure each of the devices for communication over the bus, thereby allowing the flexibility to enumerate riser cards and add new functions through peripheral devices to the computer system in which the bus is implemented.

Method and apparatus for configuring a peripheral bus

An improved interface technology is provided that may be applied to PCI (Peripheral Component Interconnect) devices connected to a southbridge. Requests are received from at least one requestor. The request require responses to be sent back to the respective requestor. The requests are placed by the respective requestor by asserting a request signal, and the request signal is deasserted by the respective requestor when a response is sent back. A retry request may be sent to the current requestor for requesting the current requestor to deassert its request signal although a response has not yet been sent back, and to reassert the request signal later. Together with the retry request, a ready signal is sent indicating whether the request could be processed. This allows the requestor to modify its request when retrying it, if the request was not yet processed.

Retry mechanism for blocking interfaces

A method and apparatus for passing device configuration information to a shared controller. In one embodiment, a host controller may be configured to read configuration from one or more peripheral devices coupled to a serial bus. The peripheral devices may include coder/decoder (codec) circuitry, and may be implemented using a riser card. The host controller may employ one or more of several different techniques in order to read configuration information from the peripheral device. The configuration information at a minimum includes a device identifier, which may identify the vendor and the function of the device. Additional information needed to configure the device to communicate over the peripheral bus may also be obtained with a read of the device, or various lookup mechanisms, such as a lookup table or a tree-like data structure. After configuration information has been obtained for each device coupled to the bus, the host controller may dynamically configure each of the devices for communication over the bus, thereby allowing the flexibility to enumerate riser cards and add new functions through peripheral devices to the computer system in which the bus is implemented.

Growing community of inventors

Ullersdorf, Germany

Joerg Winkler