INTEGRATED CIRCUIT DESIGN USING DYNAMIC VOLTAGE SCALING

• US 20150095863A1
• Filed: 10/01/2014
• Published: 04/02/2015
• Est. Priority Date: 10/02/2013
• Status: Active Grant

• Current Assignee: MaxLinear Communications, LLC (f/k/a Entropic Communications, LLC) (Maxlinear Incorporated)
• Original Assignee: Entropic Communications Incorporated (Maxlinear Incorporated)
• Inventors: Moughabghab, Raed, Petrovic, Branislav, Scott, Michael
• Granted Patent: US 9,235,678 B2
• Time in Patent Office: Days
• US Class Current: 716/109
• CPC Class Codes: G06F 2119/06 Power analysis or power optimisation
• CPC Class Codes: G06F 30/327 Logic synthesis; Behaviour synthesis, e.g. mapping logic, HDL to netlist, high-level language to RTL or netlist
• CPC Class Codes: G06F 30/398 Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] optical proximity correction [OPC] design processes G03F1/36

Abstract

A method and an apparatus from such method for designing an integrated circuit (IC) that mitigates the effects of process, voltage, and temperature dependent characteristics on the fabrication of advanced IC'"'"'s but provides high die yields, lower power usage, and faster circuits. Conventional design process takes into account power supply voltage Vdd as a variable that must be considered in a skewed corner analysis. The disclosure teaches that the IC design process can be substantially simplified by essentially factoring out voltage based variations in corner lot analysis for IC designs that include dynamic voltage scaling circuitry, because each fabricated IC die of an IC design having dynamic voltage scaling can individually adjust the applied supply voltage Vdd within a range to offset local process-induced variations in the performance of that specific IC die.

Claims

1. A method for designing an integrated circuit (“

IC”

), including the steps of;

(a) designing the IC to meet a voltage dependent frequency specification, the IC design including feedback circuitry for controlling a power supply voltage to a fabricated instance of the IC design;

(b) characterizing a fabrication process for the IC design at a range of power supply voltage levels achievable by the feedback circuitry;

(c) validating the IC design against the fabrication process if the frequency specification is achievable for essentially all instances of the IC design fabricated in accordance with the fabrication process by adjustment of the power supply voltage levels applied to such instances of the IC design within the range of the power supply voltage levels achievable by the feedback circuitry;

(d) fabricating instances of the IC design using the characterized fabrication process; and

(e) adjusting the power supply voltage of each instance of the IC design using the feedback circuitry so as to cause each such instance of the IC design to meet the frequency specification.

2. The method of claim 1, wherein the feedback circuitry includes:

(a) at least one ring oscillator distributed on an instance of the IC design for measurement of local voltage dependent characteristics, each such ring oscillator outputting a corresponding voltage dependent frequency signal;

(b) a comparator for comparison of at least one voltage dependent frequency signal to a selected reference frequency and for outputting a signal that reflects the difference in frequency between at least one ring oscillator and the selected reference frequency; and

(c) a closed-loop feedback control circuit for adjusting the power supply voltage to an instance of the IC design as a function of the comparator output signal.

3. The method of claim 1, wherein the feedback circuitry includes:

(a) means for measurement of local voltage dependent die characteristics;

(b) means for comparison of the measured characteristics to a standard; and

(c) means responsive to the comparison for feedback control of the power supply voltage for an instance of the IC design.

4. A method for designing an integrated circuit (“

IC”

), including the steps of;

(a) designing the IC to meet a voltage dependent frequency specification, the IC design including feedback circuitry for controlling a power supply voltage to a fabricated instance of the IC design;

(b) characterizing a fabrication process by means of corner lots for the IC design at a range of power supply voltage levels achievable by the feedback circuitry;

(c) validating the IC against the fabrication process if the frequency specification is achievable in all corners of the corner lots for essentially all instances of the IC design fabricated in accordance with the fabrication process by adjustment of the power supply voltage levels applied to such instances of the IC design within the range of the power supply voltage levels achievable by the feedback circuitry;

(d) fabricating instances of the IC design using the characterized fabrication process; and

(e) adjusting the power supply voltage of each instance of the IC design using the feedback circuitry so as to cause each such instance of the IC design to meet the frequency specification.

5. The method of claim 4, wherein the feedback circuitry includes:

(a) at least one ring oscillator distributed on an instance of the IC design for measurement of local voltage dependent characteristics, each such ring oscillator outputting a corresponding voltage dependent frequency signal;

(b) a comparator for comparison of at least one voltage dependent frequency signal to a selected reference frequency and for outputting a signal that reflects the difference in frequency between at least one ring oscillator and the selected reference frequency; and

(c) a closed-loop feedback control circuit for adjusting the power supply voltage to an instance of the IC design as a function of the comparator output signal.

6. The method of claim 4 wherein the feedback circuitry includes:

(a) means for measurement of local voltage dependent die characteristics;

(b) means for comparison of the measured characteristics to a standard; and

(c) means responsive to the comparison for feedback control of the power supply voltage for an instance of the IC design.

7. An integrated circuit (“

IC”

) prepared by a process comprising the steps of;

(a) designing the IC to meet a voltage dependent frequency specification, the IC design including feedback circuitry for controlling a power supply voltage to a fabricated instance of the IC;

(b) characterizing a fabrication process for the IC design at a range of power supply voltage levels achievable by the feedback circuitry;

(c) validating the IC design against the fabrication process if the frequency specification is achievable for essentially all instances of the IC design fabricated in accordance with the fabrication process by adjustment of the power supply voltage levels applied to such instances of the IC design within the range of the power supply voltage levels achievable by the feedback circuitry;

(d) fabricating the IC in accordance with the IC design using the characterized fabrication process; and

(e) adjusting the power supply voltage of the IC using the feedback circuitry so as to cause the IC to meet the frequency specification.

8. The integrated circuit (“

IC”

) of claim 7, wherein the feedback circuitry includes;

(a) at least one ring oscillator distributed on the IC for measurement of local voltage dependent characteristics, each such ring oscillator outputting a corresponding voltage dependent frequency signal;

(b) a comparator for comparison of at least one voltage dependent frequency signal to a selected reference frequency and for outputting a signal that reflects the difference in frequency between at least one ring oscillator and the selected reference frequency; and

(c) a closed-loop feedback control circuit for adjusting the power supply voltage to the IC as a function of the comparator output signal.

9. The integrated circuit (“

IC”

) of claim 7, wherein the feedback circuitry includes;

(a) means for measurement of local voltage dependent die characteristics;

(b) means for comparison of the measured characteristics to a standard; and

(c) means responsive to the comparison for feedback control of the power supply voltage for the IC.

10. An integrated circuit (“

IC”

) prepared by a process comprising the steps of;

(a) designing the IC to meet a voltage dependent frequency specification, the IC design including feedback circuitry for controlling a power supply voltage to a fabricated instance of the IC;

(b) characterizing a fabrication process by means of corner lots for the IC design at a range of power supply voltage levels achievable by the feedback circuitry;

(c) validating the IC against the fabrication process if the frequency specification is achievable in all corners of the corner lots for essentially all instances of the IC design fabricated in accordance with the fabrication process by adjustment of the power supply voltage levels applied to such instances of the IC design within the range of the power supply voltage levels achievable by the feedback circuitry;

(d) fabricating the IC using the characterized fabrication process; and

(e) adjusting the power supply voltage of the IC using the feedback circuitry so as to cause the IC to meet the frequency specification.

11. The integrated circuit (“

IC”

) of claim 10, wherein the feedback circuitry includes;

(a) at least one ring oscillator distributed on the IC for measurement of local voltage dependent characteristics, each such ring oscillator outputting a corresponding voltage dependent frequency signal;

(b) a comparator for comparison of at least one voltage dependent frequency signal to a selected reference frequency and for outputting a signal that reflects the difference in frequency between at least one ring oscillator and the selected reference frequency; and

(c) a closed-loop feedback control circuit for adjusting the power supply voltage to the IC as a function of the comparator output signal.

12. The integrated circuit (“

IC”

) of claim 10, wherein the feedback circuitry includes;

(a) means for measurement of local voltage dependent die characteristics;

(b) means for comparison of the measured characteristics to a standard; and

(c) means responsive to the comparison for feedback control of the power supply voltage for the IC.

13. An integrated circuit (“

IC”

) including feedback circuitry for controlling a power supply voltage to the IC to meet a voltage dependent frequency specification, the power supply voltage being adjustable using the feedback circuitry so as to cause the IC to meet the voltage dependent frequency specification, wherein the adjustment of the power supply voltage is determined by (1) characterization of a fabrication process for the IC at a range of power supply voltage levels achievable by the feedback circuitry, and (2) validation of the design of the IC against the fabrication process if the voltage dependent frequency specification is achievable for essentially all instances of the IC fabricated in accordance with the fabrication process by adjustment of the power supply voltage levels applied to such instances of the IC within the range of the power supply voltage levels achievable by the feedback circuitry.

14. The integrated circuit (“

IC”

) of claim 13, wherein the feedback circuitry includes;

(a) at least one ring oscillator distributed on the IC for measurement of local voltage dependent characteristics, each such ring oscillator outputting a corresponding voltage dependent frequency signal;

(b) a comparator for comparison of at least one voltage dependent frequency signal to a selected reference frequency and for outputting a signal that reflects the difference in frequency between at least one ring oscillator and the selected reference frequency; and

(c) a closed-loop feedback control circuit for adjusting the power supply voltage to the IC as a function of the comparator output signal.

15. The integrated circuit (“

IC”

) of claim 13, wherein the feedback circuitry includes;

(a) means for measurement of local voltage dependent die characteristics;

(b) means for comparison of the measured characteristics to a standard; and

(c) means responsive to the comparison for feedback control of the power supply voltage for the IC.