Controller for processing apparatus
The present invention relates to processing apparatus utilising dynamic scaling of voltage (DVS), and in particular although not exclusively to a controller for such apparatus. The invention is especially applicable to software defined radio (SDR), but is not so limited and may be applied to other re-configurable electronic systems. The present invention provides a controller for a processing apparatus having a plurality of processing resources, at least some of said resources having controllable supply voltage and/or frequency; the controller comprising: means for scheduling operations on said resources, at least some of said operations having a predetermined deadline by which the operation must be performed; means for determining a voltage and/or frequency profile for a said operation having a said deadline; and means for instructing the resources to perform said operations according to said schedule and said profile.
1. A controller for a processing apparatus having a plurality of processing resources, comprising:
a processor or control code for a processor arranged to schedule operations on said processing resources;
a processor or control code for a processor arranged to determine, for an operation having a deadline, a voltage-frequency profile based an average cycle count and a standard deviation of the average cycle count of the operation; and
a processor or control code for a processor arranged to instruct the processing resources to perform said operation according to said schedule and said profile.
2. A controller according to claim 1 wherein the profile is arranged to minimise the average power consumed by the apparatus in performing the operation.
3. A controller according to claim 1 wherein the voltage-frequency profile has more than two voltage or frequency operating points.
4. A controller according to claim 1 wherein the voltage-frequency profile includes voltage or frequency operating points which increase over an execution time of the operation.
5. A controller according to claim 4 wherein the voltage-frequency profile increases the voltage or frequency operating points if the operation has not been completed within the average cycle count of the operation.
6. A controller according to claim 1 , comprising:
an operation control data structure comprising a record corresponding to the operation, the record comprising a worst case cycle count of the operation.
7. A controller according to claim 1 , comprising:
a voltage-frequency profile calculator arranged to calculate said voltage-frequency profile for said operation based on a worst case cycle count of the operation, the average cycle count of the operation, and the standard deviation of the average count.
8. A controller according to claim 7 , further comprising:
a processor or control code for a processor arranged to quantise the voltage-frequency profile determined by the calculator to correspond to available voltage and/or frequency operating points of the processing resources.
9. A controller according to any claim 1 , comprising:
a process timetable having a control message for the processing resources, the control message corresponding to the operation and containing voltage and/or frequency control instructions.
10. The controller of claim 1 , wherein said voltage-frequency profile is periodically updated.
11. A processing apparatus having a plurality of processing resources, comprising:
a processor or control code for a processor arranged to schedule operations on said processing resources;
a processor or control code for a processor arranged to determine a voltage-frequency profile for an operation having a deadline based on an average cycle count and a standard deviation of the average cycle count of the operation; and
a processor or control code for a processor arranged to instruct the processing resources to perform said operation according to said schedule and said profile.
12. An apparatus according to claim 11 , comprising a wireless terminal or base station.
13. The processing apparatus of claim 11 , wherein said voltage-frequency profile is periodically updated.
14. A computer program product carrying code for configuring a configurable device having a controller for a processing apparatus having a plurality of processing resources, comprising:
a processor or control code for a processor arranged to schedule operations on said processing resources;
a processor or control code for a processor arranged to determine, for an operation having a deadline, a voltage-frequency profile based on an average cycle count and a standard deviation of the average cycle count of the operation; and
a processor or control code for a processor arranged to instruct the processing resources to perform said operation according to said schedule and said profile.
15. The computer program product of claim 14 , wherein said voltage-frequency profile is periodically updated.
16. A method of controlling a processing apparatus having a plurality of processing resources, comprising:
scheduling operations on said resources;
determining, for an operation having a deadline, a voltage-frequency profile based on an average cycle count and a standard deviation of the average cycle count of the operation; and
instructing the resources to perform said operation according to said schedule and said profile.
17. A method according to claim 16 wherein the profile is arranged to minimise the average power consumed by the apparatus in performing the operation.
18. A method according to claim 16 wherein the voltage-frequency profile has more than two voltage or frequency operating points.
19. A method according to claim 16 wherein the voltage-frequency profile includes voltage or frequency operating points which increase over the execution time of the operation.
20. A method according to claim 19 wherein the voltage-frequency profile increases the voltage or frequency operating points if the operation has not been completed within the average cycle count of the operation.
21. A method according to claim 16 wherein said determining comprises:
generating an operation control data-structure comprising a record corresponding to the operation, the record comprising a worst case cycle count of the operation.
22. A method according to claim 21 wherein each record comprises a voltage and/or frequency profile.
23. A method according to claim 16 wherein the determining comprises:
calculating said voltage-frequency profile for said operation based on a worst case cycle count of the operation, the average cycle count of the operation, and the standard deviation of the average count.
24. A method according to claim 23 wherein the determining further comprises:
quantising the calculated voltage-frequency profile to correspond to available voltage and/or frequency operating points of the resources.
25. A method according to claim 16 wherein the scheduling comprises:
generating a process timetable having a control message for the resources, the control message corresponding to the operation and containing voltage and/or frequency control instructions.
26. A method according to claim 16 wherein the processing apparatus is a wireless terminal or base station.
27. The method of claim 16 , wherein said voltage-frequency profile is periodically updated.
28. A computer readable medium storing a computer code readable by a processor in order to carry out a method of controlling a processing apparatus having a plurality of processing resources, comprising:
scheduling operations on said resources;
determining, for an operation having a deadline, a voltage-frequency profile based on an average cycle count and a standard deviation of the average cycle count of the operation;
instructing the resources to perform said operation according to said schedule and said profile.
29. The computer readable storage medium of claim 28 , wherein said voltage-frequency profile is periodically updated.