System and method for transferring data streams simultaneously on multiple buses in a computer system

• US 5,682,484 A
• Filed: 11/20/1995
• Issued: 10/28/1997
• Est. Priority Date: 11/20/1995
• Status: Expired due to Term

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Lambrecht, Andy
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): Etienne, Ario
• Application Number:
  US08/559,664
• Time in Patent Office: 708 Days
• Field of Search: 395/306, 395/308, 395/847, 395/841, 395/855, 395/858, 395/309, 395/281, 395/822, 395/840, 395/162, 395/163, 395/200.09, 395/154, 395/200.04, 395/200.12, 370/85.13, 370/85.9, 370/85.11, 364/514, 463/43
• US Class Current: 710/311
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence

Abstract

A computer system optimized for real-time applications which provides increased performance over current computer architectures. The system includes a standard local system bus, such as the PCI bus, and also includes a dedicated real-time bus or multimedia bus. Thus multimedia devices such as video cards, audio cards, etc., as well as communications devices, transfer real-time data through a separate bus without requiring arbitration for the PCI bus. The computer system of the present invention thus provides much greater performance for real-time applications than prior systems. In various embodiments, multimedia devices transmit addressing and control information for a multimedia bus transfer either over the PCI bus or using a separate serial control channel. The multimedia bus may also comprise separate multimedia channels for different data types. Methods are also disclosed for transferring periodic multimedia data over the multimedia bus.

Claims

1. A method for transferring data on multiple buses in a computer system, wherein the computer comprises a CPU, main memory coupled to the CPU which stores data accessible by the CPU, bridge logic coupled to the CPU and the main memory, an expansion bus coupled to the bridge logic which transfers data, a multimedia bus which transfers multimedia data, and a plurality of multimedia devices coupled to the expansion bus and the multimedia bus, the method comprising:

a first multimedia device generating addressing and control signals on the expansion bus for a bus transfer, wherein the bus transfer is intended for a second multimedia device;

the first multimedia device generating one or more signals on the expansion bus indicating a multiple bus transfer is desired, including one or more signals indicating respective byte lanes where said multiple bus transfer will occur;

the second multimedia device receiving the addressing and control signals on the expansion bus for the multimedia bus transfer;

the second multimedia device providing one or more signals on the expansion bus to the first multimedia device indicating said multiple bus transfer can proceed, wherein said providing one or more signals on the expansion bus to the first multimedia device indicating said multiple bus transfer can proceed occurs in response to the second multimedia device receiving the one or more signals on the expansion bus indicating said multiple bus transfer is desired;

the first multimedia device performing a plurality of multimedia bus transfers comprising multimedia data, wherein said plurality of multimedia bus transfers comprise transfers simultaneously on data lines of both the expansion bus and the multimedia bus, wherein said transfers simultaneously on data lines of both the expansion bus and the multimedia bus are performed in response to said generating one or more signals on the bus indicating a multiple bus transfer is desired.

2. The method of claim 1, further comprising:

the second multimedia device determining if the second multimedia device can guarantee availability to receive data on both the expansion bus and the multimedia bus;

wherein the second multimedia device providing said one or more signals on the bus to the first multimedia device indicating said multiple bus transfer can proceed is performed in response to the second multimedia device determining that the second multimedia device can guarantee availability to receive data on both the expansion bus and the multimedia bus.

3. A method for transferring data on multiple buses in a computer system, wherein the computer comprises a CPU, main memory coupled to the CPU which stores data accessible by the CPU, bridge logic coupled to the CPU and the main memory, an expansion bus coupled to the bridge logic which transfers data, a multimedia bus which transfers multimedia data, and a plurality of multimedia devices coupled to the expansion bus and the multimedia bus, the method comprising:

a first multimedia device generating addressing and control signals on the expansion bus for a bus transfer, wherein the bus transfer is intended for a second multimedia device;

the first multimedia device generating one or more signals on the expansion bus indicating a multiple bus transfer is desired;

the second multimedia device receiving the addressing and control signals on the expansion bus for the multimedia bus transfer;

the first multimedia device performing a plurality of multimedia bus transfers, wherein said plurality of multimedia bus transfers comprise transfers simultaneously on data lines of both the expansion bus and the multimedia bus, wherein said transfers simultaneously on data lines of both the expansion bus and the multimedia bus are performed in response to said generating one or more signals on the bus indicating a multiple bus transfer is desired, wherein said multimedia bus transfers comprise transfers of periodic multimedia data, and wherein said periodic multimedia data comprises motion video data at a plurality of frames per second, and said periodic multimedia data comprises audio data at a plurality of cycles per second.

4. The method of claim 3, wherein said multiple bus transfers comprise transferring said motion video data on a first one of either said expansion bus or said multimedia bus, and also transferring said audio data on the other of either said expansion bus or said multimedia bus.

5. A computer system, comprising:

a CPU;

main memory coupled to the CPU which stores data accessible by the CPU;

bridge logic coupled to the CPU and to the main memory, wherein the bridge logic includes a memory controller coupled to the main memory and also includes expansion bus interface logic;

an expansion bus coupled to the bridge logic, wherein said expansion bus includes a plurality of data lines and control lines;

a multimedia bus which transfers multimedia data;

a plurality of multimedia devices coupled to said expansion bus and to said multimedia bus, wherein each of said multimedia devices perform operations on said expansion bus and said multimedia bus, wherein each of said multimedia devices includes;

means for generating one or more signals on the expansion bus to a target multimedia device indicating a transfer comprising multimedia data is desired;

means for generating one or more signals on the expansion bus to a target multimedia device indicating a multiple bus transfer is desired, wherein said one or more signals regarding said multiple bus transfer includes information indicating respective byte lanes where said multiple bus transfers will occur;

means for receiving one or more signals on the expansion bus from a source multimedia device indicating a transfer comprising multimedia data is desired;

means for receiving one or more signals on the expansion bus from a source multimedia device indicating a multiple bus transfer is desired;

means for performing a plurality of multiple bus transfers comprising multimedia data to the target multimedia device using both the expansion bus and the multimedia bus, wherein said plurality of multiple bus transfers using both the expansion bus and the multimedia bus are performed in response to operation of said means for generating one or more signals on the expansion bus to a target multimedia device indicating a multiple bus transfer is desired.

6. The computer system of claim 5, wherein said means for receiving determines if the multimedia device can guarantee availability to receive data on both the expansion bus and the multimedia bus;

wherein said means for receiving provides one or more signals on the expansion bus to the source multimedia device indicating said multiple bus transfer can proceed in response to the means for receiving determining that the multimedia device can guarantee availability to receive data on both the expansion bus and the multimedia bus.

7. A computer system, comprising:

a CPU;

main memory coupled to the CPU which stores data accessible by the CPU;

bridge logic coupled to the CPU and to the main memory, wherein the bridge logic includes a memory controller coupled to the main memory and also includes expansion bus interface logic;

an expansion bus coupled to the bridge logic, wherein said expansion bus includes a plurality of data lines and control lines;

a multimedia bus which transfers multimedia data;

a plurality of multimedia devices coupled to said expansion bus and to said multimedia bus, wherein each of said multimedia devices perform operations on said expansion bus and said multimedia bus, wherein each of said multimedia devices includes;

means for generating one or more signals on the expansion bus to a target multimedia device indicating a transfer comprising multimedia data is desired;

means for generating one or more signals on the expansion bus to a target multimedia device indicating a multiple bus transfer is desired;

means for receiving one or more signals on the expansion bus from a source multimedia device indicating a transfer comprising multimedia data is desired;

means for receiving one or more signals on the expansion bus from a source multimedia device indicating a multiple bus transfer is desired;

means for performing a plurality of multiple bus transfers comprising multimedia data to the target multimedia device using both the expansion bus and the multimedia bus, wherein said plurality of multiple bus transfers using both the expansion bus and the multimedia bus are performed in response to operation of said means for generating one or more signals on the bus to a target multimedia device indicating a multiple bus transfer is desired, and wherein said multimedia bus transfers comprise transfers of periodic multimedia data, wherein said periodic multimedia data comprises motion video data at a plurality of frames per second and said periodic multimedia data also comprises audio data at a plurality of cycles per second.

8. The method of claim 7, wherein said means for performing said multiple bus transfers transfers said motion video data on a first one of either said expansion bus or said multimedia bus, and also transfers said audio data on the other of either said expansion bus or said multimedia bus.