INTERFACE TO REGULATE VOLTAGE FOR ASIC POWER MANAGEMENT

• US 20100090743A1
• Filed: 10/10/2008
• Published: 04/15/2010
• Est. Priority Date: 10/10/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Ataee, Mehran, Harisharan, Udupi, Somasundaram, Senthil, Qian, Jun, Hamilton, Thomas A.
• Granted Patent: US 8,264,210 B2
• Time in Patent Office: Days
• US Class Current: 327/306
• CPC Class Codes: H03K 19/00369 Modifications for compensating variations of temperature, supply voltage or other physical parameters

Abstract

A method and apparatus to regulate voltage used to power an ASIC comprising an ASIC having a signal source and a modulator. The modulator establishes a characteristic of a signal created by the signal source to indicate a voltage level to be used to power the ASIC. The signal is communicated to a voltage regulator to apply an optimal voltage to the ASIC.

Claims

1. An apparatus comprising:

an ASIC having a signal source and a modulator, wherein the modulator establishes a characteristic of a signal created by the signal source to indicate a voltage level to be used to power the ASIC.

2. The apparatus of claim 1 wherein the signal is a repeating signal.

3. The apparatus of claim 1 wherein the characteristic is a frequency.

4. The apparatus of claim 3 wherein the characteristic is a product of the frequency and a modulation factor, where the modulation factor represents the voltage level.

5. The apparatus of claim 1 wherein the characteristic is a duty cycle.

6. The apparatus of claim 5, wherein the characteristic is a product of the duty cycle and a modulation factor, where the modulation factor represents the voltage level.

7. The apparatus of claim 6 wherein the modulation factor establishes a duty cycle in a range of between 0% to 100%.

8. The apparatus of claim 1 further comprising a single conductor coupling the ASIC to a voltage regulator, wherein the single conductor carries the signal.

9. The apparatus of claim 1 wherein the characteristic is time invariant.

10. The apparatus of claim 1 wherein the characteristic is time variant.

11. The apparatus of claim 1 wherein the ASIC provides a reference clock for use in establishing the voltage level.

12. The apparatus of claim 11 wherein the reference clock and the signal are coupled to a voltage regulator via two conductors.

13. The apparatus of claim 1 wherein the voltage level is an optimal voltage level for efficiently operating the ASIC.

14. A method of operating an ASIC comprising:

applying a first voltage level to the ASIC;

sending a repeating signal from the ASIC to a voltage regulator, wherein the repeating signal has a characteristic identifying a second voltage level; and

adjusting the first voltage level to the second voltage level in response to the characteristic.

15. The method of claim 14 wherein the second voltage level is an optimal voltage level for efficiently operating the ASIC.

16. The method of claim 14 wherein the characteristic is a frequency.

17. The method of claim 14 wherein the characteristic is a duty cycle.

18. The method of claim 14 wherein the sending step uses a single conductor to carry the signal.

19. The method of claim 14 further comprising:

generating a reference signal;

sending the reference signal to the voltage regulator to be used in combination with the signal to determine the characteristic.

20. The method of claim 19 wherein the signal and reference signal are carried on two conductors to a voltage regulator.