Device having priority upgrade mechanism capabilities and a method for updating priorities

• US 8,078,781 B2
• Filed: 08/23/2006
• Issued: 12/13/2011
• Est. Priority Date: 08/23/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Goren, Ori, Netanel, Yaron, Livay, Aviel, Moran, Gil, Neeman, Yossy
• Primary Examiner(s): Rinehart, Mark
• Assistant Examiner(s): HUYNH, KIM T
• Application Number:
  US12/377,806
• Publication Number:
  US 20100199010A1
• Time in Patent Office: 1,938 Days
• Field of Search: 710/200, 710240-244
• US Class Current: 710/244
• CPC Class Codes: G06F 13/364 using independent requests or grants, e.g. using separated request and grant lines

Abstract

A device having priority update capabilities and a method for updating priorities, the method includes: receiving a request to update to a requested priority, priorities of transaction requests stored within a first sequence of pipeline stages that precede an arbiter; updating a priority level of a transaction request stored in the first sequence to the requested priority if the transaction request is priority upgradeable and if the requested priority is higher that a current priority of the transaction request; and arbitrating between transaction requests in response to priority attributes associated with the transaction requests.

Claims

1. A device having priority update capabilities, the device comprises:

an arbiter adapted to arbitrate between a plurality of transaction requests in response to priority attributes associated with the transaction requests; and

a first sequence of pipeline stages that precede the arbiter, at least one pipeline stage of the first sequence of pipeline stages being adapted to receive a request to update a priority of a particular transaction request of the plurality of transaction requests that is stored within the at least one pipeline stage to a requested priority; and

the device being adapted to;

update the priority of the particular transaction request stored in the at least one pipeline stage for a particular arbitration cycle, if the particular transaction request is priority upgradeable and if the requested priority is higher than a current priority of the particular transaction request; and

selectively mask another transaction request stored in the at least one pipeline stage for the particular arbitration cycle.

2. The device according to claim 1 wherein each transaction request of the plurality of transaction requests is associated with a priority level attribute and a priority upgradeability attribute.

3. The device according to claim 1 wherein the first sequence of pipeline stages comprises multiple modular components;

whereas each modular component is adapted to support a certain point-to-point protocol.

4. The device according to claim 1 further comprising a time based priority level upgrading module adapted to upgrade a priority of a priority upgradeable transaction request in response to a time period that the priority upgradeable transaction request is pending in the first sequence.

5. The device according to claim 4 wherein the time based priority level upgrading module is adapted to perform multiple increments of the priority upgrades of the priority upgradeable transaction request, wherein a time difference between consecutive priority upgrades is inversely proportional to a number of priority increases.

6. The device according to claim 1 wherein the first sequence comprises components of multiple interconnects.

7. The device according to claim 1 wherein the device comprises multiple input ports, multiple output ports, and multiple modular components;

whereas each modular component is adapted to support a certain point-to-point protocol;

whereas at least one modular component comprises a sampling circuit and a bypass circuit, whereas the sampling circuit is selectively bypassed by the bypass circuit.

8. The device according to claim 7 wherein the modular components further comprise S splitters, wherein each splitter is adapted to optimize transactions towards a slave associated with the splitter.

9. The device according to claim 8 wherein the multiple modular components comprise M expanders, whereas different expanders are coupled to different masters, and wherein each expander is coupled in parallel to S arbiters and multiplexers.

17. The device according to claim 2 wherein the first sequence of pipeline stages comprises multiple modular components;

whereas each modular component is adapted to support a certain point-to-point protocol.

10. A method for updating priorities, the method comprises:

arbitrating between a plurality of transaction requests in response to priority attributes associated with the plurality of transaction requests;

receiving a request to update to a requested priority of a particular transaction request of the plurality of transaction requests stored within a first pipeline stage of a plurality of pipeline stages that precede an arbiter;

updating the particular transaction request stored in the first pipeline stage for a particular arbitration cycle, to the requested priority if the particular transaction request is priority upgradeable and if the requested priority is higher that a current priority of the particular transaction request; and

selectively masking another transaction request stored in the first pipeline stage for the particular arbitration cycle.

11. The method according to claim 10 wherein the updating comprises checking a priority level attribute and a priority upgradeability attribute associated with the particular transaction request.

12. The method according to claim 10 wherein the updating comprises updating priorities of transaction requests stored within multiple modular components that are adapted to support a certain point-to-point protocol.

13. The method according to claim 10 further comprising performing a priority level upgrade of a priority upgradeable transaction request in response to a time period the priority upgradeable transaction request is pending.

14. The method according to claim 13 wherein performing the priority level upgrade comprises repetitively incrementing the priority level of upgradeable transaction requests wherein a time difference between consecutive priority upgrades is inversely proportional to a number of priority increases.

15. The method according to claim 11 wherein the updating comprises updating priorities of transaction requests stored within multiple modular components that are adapted to support a certain point-to-point protocol.

16. The method according to claim 11 further comprising performing a priority level upgrade of a priority upgradeable transaction request in response to a time period the priority upgradeable transaction request is pending.