DYNAMIC PROGRAMMABLE DELAY SELECTION CIRCUIT AND METHOD

• US 20110047402A1
• Filed: 10/29/2010
• Published: 02/24/2011
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: CARNEY, John C.
• Granted Patent: US 8,082,463 B2
• Time in Patent Office: Days
• US Class Current: 713/501
• CPC Class Codes: G06F 1/10 Distribution of clock signals , e.g. skew
• CPC Class Codes: H03K 2005/00156 using opamps, comparators, voltage multipliers or other analog building blocks
• CPC Class Codes: H03K 5/131 Digitally controlled

Abstract

A controller may include a measurement circuit configured to generate a proxy signal representing delay variations in the controller. The measurement circuit may also generate a measurement value from the proxy signal. A control circuit may be configured to convert the measurement value into a control value. A delay circuit may be adjusted by the control value to alter an amount of delay of a signal.

Claims

1. A system, comprising:

a memory to generate a timing signal;

a delay circuit to delay a first portion of the timing signal by a first amount based on a control signal;

a measurement circuit to measure one or more parameters of the system and generate a measurement value; and

a control circuit to convert the measurement value into the control signal for the delay circuit.

2. The system of claim 1, where the memory includes a random access memory (RAM) device.

3. The system of claim 1, where the delay circuit is further configured to delay a second portion of the timing signal by a second amount that is different than the first amount based on the control signal.

4. The system of claim 3, where the delay circuit includes:

a first delay line configured to delay the first portion of the timing signal by the first amount, the first amount being determined by the control signal, and

a second delay line configured to delay the second portion of the timing signal by the second amount, the second amount being determined by the control signal.

5. The system of claim 1, where the measurement circuit includes:

a clock circuit configured to generate a toggle signal, and

a measurement portion triggered by the toggle signal to measure a delay amount and generate the measurement value.

6. The system of claim 5, where the measurement value is proportional to a change in the delay amount.

7. The system of claim 1, where the control circuit includes:

a table that is indexed by the measurement value to produce the control signal.

8. The system of claim 7, where the measurement value is proportional to an amount of delay within the measurement circuit.

9. The system of claim 7, where values in the table are programmable.

10-20. -20. (canceled)

21. A method, performed by a device, the method comprising:

measuring one or more parameters of the system;

generating a measurement value based on the measured one or more parameters; and

converting the measurement value into a control signal for delaying;

generating a timing signal; and

delaying a first portion of the timing signal by a first amount based on the control signal.

22. The method of claim 21, further comprising:

delaying a second portion of the timing signal by a second amount that is different than the first amount based on the control signal.

23. The method of claim 22, further comprising:

indexing a table, by the measurement value, to produce the control signal.

24. The method of claim 21, further comprising:

generating a toggle signal, and

measuring, based on the toggle signal, a delay amount, where

generating the measurement value is further based on the delay amount.

25. The method of claim 24, where the measurement value is proportional to a change in the delay amount.

26. The method of claim 21, where the measurement value is proportional to an amount of delay.

27. A method, performed by a device, the method comprising:

measuring an operating condition of a system;

determining an adjustment value from the measured operating condition, including mapping a plurality of measured operating conditions to and a plurality of adjustment values; and

controlling an actuator circuit based on the adjustment value.

28. The method of claim 27, where controlling the actuator circuit comprises:

varying an amount of delay in a variable delay line associated with the actuator circuit based on the adjustment value.

29. The method of claim 27, where controlling the actuator circuit comprises:

changing the operating condition based on the adjustment value.

30. The method of claim 29, where changing the operating condition includes:

adjusting one or more a clock frequency, a voltage, or a temperature with the actuator circuit based on the adjustment value.

31. The method of claim 27, where determining the adjustment value includes mapping between the plurality of measured operating conditions and the plurality of adjustment values using a table.