Method, apparatus, and system for multi-line communication

• US 20030126331A1
• Filed: 01/03/2002
• Published: 07/03/2003
• Est. Priority Date: 01/03/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Levy, Paul S.
• Granted Patent: US 6,868,464 B2
• Time in Patent Office: Days
• US Class Current: 710/107
• CPC Class Codes: G06F 13/4273 using a clocked protocol

Abstract

According to one aspect of the invention, a method is provided in which one or more requests are received to transmit data between a first device and a second device via a bus having a plurality of data lines. A first number of data lines is assigned for data transmission from the first device to the second device and a second number of data lines is assigned for data transmission from the second device to the first device, based upon a set of rules. Data are transmitted from the first device to the second device using the first number of data lines and from the second device to the first device using the second number of data lines.

Claims

1. A method comprising:

receiving one or more requests to transmit data between a first device and a second device via a link having a plurality of data lines;

assigning a first number of data lines for data transmission from the first device to the second device and a second number of data lines for data transmission from the second device to the first device, based upon a set of rules; and

transmitting data from the first device to the second device using the first number of data lines and from the second device to the first device using the second number of data lines.

2. The method of claim 1 wherein the one or more requests includes a request to transmit data from the first device to the second device.

3. The method of claim 1 wherein the one or more requests includes a request to transmit data from the second device to the first device.

4. The method of claim 1 wherein assigning includes:

determining a particular rule from the set of rules based on one or more factors; and

determining the first number of data lines and the second number of data lines based on the particular rule determined.

5. The method of claim 4 wherein the one or more factors are selected from the group consisting of a first factor corresponding to the type of the respective request, a second factor corresponding to the priority of the respective request, and a third factor corresponding to how much data waiting for transmission in a transmit queue associated with the respective device.

6. The method of claim 1 wherein assigning includes:

configuring the first number of data lines for data transmission from the first device to the second device; and

configuring the second number of data lines for data transmission from the second device to the first device.

7. The method of claim 1 wherein assigning includes:

determining if whether the one or more requests includes only a request to transmit data from the first device to the second device; and

if the one or more requests includes only a request to transmit data from the first device to the second device, assigning all data lines for data transmission from the first device to the second device.

8. The method of claim 1 wherein assigning includes:

determining if whether the one or more requests includes only a request to transmit data from the second device to the first device; and

if the one or more requests includes only a request to transmit data from the second device to the first device, assigning all data lines for data transmission from the second device to the first device.

9. A method comprising:

determining whether a first component and a second component both request to transfer data to each other at the same time via a bus having a plurality of data lines;

if only the first component requests to transfer data to the second component, allocating all of the plurality of data lines for data transfer from the first component to the second component;

if only the second component requests to transfer data to the first component, allocating all of the plurality of data lines for data transfer from the second component to the first component; and

if both the first component and the second component request to transfer data to each other at the same time, allocating a first portion of the plurality of data lines for data transfer from the first component to the second component and a second portion of the plurality of data lies for data transfer from the second component to the first component, the first portion and the second portion being determined based upon one or more criteria.

10. The method of claim 9 wherein the one or more criteria are selected from the group consisting of a first criterion corresponding to the type of the respective request, a second criterion corresponding to the priority of the respective request, and a third criterion corresponding to the depth of a transmit queue associated with the respective device.

11. The method of claim 9 wherein allocating includes:

applying a particular rule from a set of predetermined rules based upon the one or more criteria to determine the first portion and the second portion.

12. An apparatus comprising:

a first device;

a second device; and

a bus coupled to the first device and the second device, the bus having a plurality of data lines being used for data transfer between the first device and the second device, the direction of data flow for each data line being changeable based upon one or more factors corresponding to the demand to transfer data of each respective device.

13. The apparatus of claim 12 wherein the direction of data flow for each data line is set according a predetermined rule being selected based upon the one or more factors.

14. The apparatus of claim 12 wherein the one or more factors are selected from the group consisting of a first factor corresponding to the type of the respective request, a second factor corresponding to the priority of the respective request, and a third factor corresponding to how much data waiting for transmission in a transmit queue associated with the respective device.

15. The apparatus of claim 12 wherein, if only the first device requests to transfer data to the second device, all data lines are set for the data flow direction from the first device to the second device.

16. The apparatus of claim 12 wherein, if only the second device requests to transfer data to the first device, all data lines are set for the data flow direction from the second device to the first device.

17. The apparatus of claim 12 wherein, if both the first and second devices request to transfer data at the same time, a number of data lines for each data flow direction is set based upon the one or more factors corresponding to the demand to transfer data for each respective device.

18. A system comprising:

a first communication device including;

a first driver; and

a first control unit coupled to the first driver;

a second communication device including;

a second driver; and

a second control unit coupled to the second driver; and

a bus coupled to the first driver and the second driver for data transfer between the first driver and the second driver, the bus including a plurality of data lines wherein a number of data lines being assigned for data transfer in each direction varies based upon one or more criteria corresponding to a data transfer demand associated with each respective communication device.

19. The system of claim 18 wherein the first control unit instructs the first driver which data lines are used for data transfer from the first driver to the second driver.

20. The system of claim 18 wherein the second control unit instructs the second driver which data lines are used for data transfer from the second driver to the first driver.

21. The system of claim 18 wherein the one or more criteria are selected from the group consisting of a first criterion corresponding to the type of the respective request, a second criterion corresponding to the priority of the respective request, and a third criterion corresponding to the depth of a transmit queue associated with the respective device.

22. The system of claim 18 wherein the first control unit and the second control unit cooperate to determine the direction of data transfer for each data line based upon the one or more criteria.

23. The system of claim 22 wherein one of the first and second control units operates as a master control unit and the other operates as a slave control unit.

24. The system of claim 18 wherein the one or more criteria are used to select a particular rule from a set of predetermined rules to control the direction of each data line.

25. The system of claim 24 wherein a rule change can be requested by either control unit.

26. The system of claim 25 wherein a rule change is applied on a transaction by transaction basis.

27. The system of claim 26 wherein a rule change is applied on a token by token basis.

28. A machine-readable medium comprising instructions which, when executed by a machine, cause the machine to perform operations including:

receiving one or more requests to transmit data between a first device and a second device via a bus having a plurality of data lines;

assigning a first number of data lines for data transmission from the first device to the second device and a second number of data lines for data transmission from the second device to the first device, based upon a set of rules; and

transmitting data from the first device to the second device using the first number of data lines and from the second device to the first device using the second number of data lines.

29. The machine-readable medium of claim 28 wherein assigning includes:

determining a particular rule from the set of rules based on one or more factors; and

determining the first number of data lines and the second number of data lines based on the particular rule determined.

30. The machine-readable medium of claim 29 wherein the one or more factors are selected from the group consisting of a first factor corresponding to the type of the respective request, a second factor corresponding to the priority of the respective request, and a third factor corresponding to how much data waiting for transmission in a transmit queue associated with the respective device.