Semiconductor process and performance sensor
Disclosed are techniques that can be used in a semiconductor chip to determine performance such as timing performance. Among other features, supply voltages and clock rates may be adjusted to accommodate the operating temperature and to compensate for the processing variations that occurred when that chip was produced, or may occur as the chip is used. The techniques include determining a series of variables that affect performance, determining the sensitivity of timing paths in the circuit to each variable, duplicating the most sensitive paths. A novel sensor circuit is produced that includes the sensitive paths, which can be used to determine when the chip is performing as required and when it is not, and adjusting one or more supply voltages and/or clock rates in a static or real time manner when the circuit is not performing as required.
1. A performance sensor apparatus, comprising:
a plurality of timing paths, wherein each timing path has an input and an output, and wherein each timing path is representative of a path in a semiconductor circuit, each timing path associated with a particular parameter dependent on one or more of a temperature or a semiconductor process;
a logic circuit having a plurality of inputs and at least one output, wherein the output from each of the timing paths is coupled to an input of the logic circuit;
a trigger circuit having a clock input obtained from the output of the logic circuit; and
a timing circuit having an input that is related to the output of the logic circuit and having an output that changes from a first level to a second level upon a determination that a timing requirement for at least one of the timing paths is not met.
2. The apparatus of claim 1 , wherein the timing paths are implemented using combinational logic circuits.
3. The apparatus of claim 1 , wherein the logic circuit comprises:
an AND gate configured to receive each of the plurality of inputs of the logic circuit, the AND gate having an output; and
an OR gate configured to receive each of the plurality of inputs of the logic circuit, the OR gate having an output, wherein the outputs of the AND gate and the OR gate are coupled to the at least one output of the logic circuit.
4. The apparatus of claim 3 , wherein the outputs of the AND gate and the OR gate are coupled to inputs of an exclusive NOR gate, and the output of the exclusive NOR gate is connected to the at least one output of the logic circuit.
5. The apparatus of claim 1 , wherein an output of the trigger circuit is operable to provide a trigger signal to a launch flip flop for one or more of the timing paths.
6. The apparatus of claim 1 , wherein the input of the timing circuit is configured to receive a logical inverse of the output of the logic circuit.
7. The apparatus of claim 1 , further including one or more programmable or fixed delay circuits positioned after the output of the one or more timing paths to provide further adjustment for a delay margin of the performance sensor apparatus.
8. The apparatus of claim 1 , wherein each timing path represents a most sensitive path with respect to the particular parameter associated with that path, wherein the most sensitive path is characterized as having a largest amount of slack change for the particular parameters compared to other paths.
9. A performance sensor apparatus, comprising:
a plurality of timing paths, wherein each timing path has an input and an output, and wherein each timing path is representative of a path in a semiconductor circuit, each timing path associated with a particular parameter dependent on one or more of a temperature or a semiconductor process;
a logic circuit having a plurality of inputs and at least one output, wherein the output from each of the timing paths is coupled to an input of the logic circuit;
a trigger circuit having a clock input obtained from the output of the logic circuit; and
a timing circuit having an input that is related to the output of the logic circuit and having an output that changes from a first level to a second level upon a determination that a timing requirement for at least one of the timing paths is not met, the performance sensor apparatus further including a clock adjustment circuit including:
an input configured to receive a system clock,
a launch clock output coupled to each of the timing paths, and
a capture clock output coupled to a clock input of the timing circuit, wherein the clock adjustment circuit is configured to apply one or more of a clock skew adjustment, clock inversion or a margin adjustment in generating the launch clock or the capture clock.
10. The apparatus of claim 9 , wherein the clock adjustment circuit includes one or more programmable delay circuits.
11. The apparatus of claim 9 , wherein the logic circuit comprises:
an AND gate configured to receive each of the plurality of inputs of the logic circuit, the AND gate having an output; and
an OR gate configured to receive each of the plurality of inputs of the logic circuit, the OR gate having an output, wherein the outputs of the AND gate and the OR gate are coupled to the at least one output of the logic circuit.
12. The apparatus of claim 11 , wherein the outputs of the AND gate and the OR gate are coupled to inputs of an exclusive NOR gate, and the output of the exclusive NOR gate is connected to the at least one output of the logic circuit.
13. The apparatus of claim 9 , wherein the input of the timing circuit is configured to receive a logical inverse of the output of the logic circuit.
14. The apparatus of claim 9 , further including one or more programmable or fixed delay circuits positioned after the output of the one or more timing paths to provide further adjustment for a delay margin of the performance sensor apparatus.
15. The apparatus of claim 9 , wherein each timing path represents a most sensitive path with respect to the particular parameter associated with that path, wherein the most sensitive path is characterized as having a largest amount of slack change for the particular parameters compared to other paths.
16. The apparatus of claim 9 , wherein an output of the trigger circuit is operable to provide a trigger signal to a launch flip flop for one or more of the timing paths.
17. A system for sensing performance of a semiconductor circuit, the system comprising:
a performance sensor, comprising:
a system clock input configured to receive a clock signal,
a plurality of timing paths, wherein each timing path has an input and an output, each timing path is representative of a path in a semiconductor circuit and each timing path is associated with a particular parameter dependent on one or more of a temperature or a semiconductor process,
a logic circuit having a plurality of inputs and at least one output, wherein the output from each of the timing paths is coupled to an input of the logic circuit,
a trigger circuit having a clock input obtained from the output of the logic circuit, and
a timing circuit having an input that is related to the output of the logic circuit and having an output that changes from a first level to a second level upon a determination that a timing requirement for at least one of the timing paths is not met; and
a voltage regulator circuit coupled to the output of the performance sensor, the voltage regulator configured to receive a supply voltage and to adjust a value of the supply voltage provided to the semiconductor circuit based on the output of the performance sensor.
18. The system of claim 17 , wherein the logic circuit comprises:
an AND gate configured to receive each of the plurality of inputs of the logic circuit, the AND gate having an output; and
an OR gate configured to receive each of the plurality of inputs of the logic circuit, the OR gate having an output, wherein the outputs of the AND gate and the OR gate are coupled to the at least one output of the logic circuit.
19. The system of claim 18 , wherein the outputs of the AND gate and the OR gate are coupled to inputs of an exclusive NOR gate, and the output of the exclusive NOR gate is connected to the at least one output of the logic circuit.
20. The system of claim 17 , wherein an output of the trigger circuit is operable to provide a trigger signal to a launch flip flop for one or more of the timing paths.
21. The system of claim 17 , further including a clock adjustment circuit including:
an input coupled to the system clock input,
a launch clock output coupled to each of the timing paths, and
a capture clock output coupled to a clock input of the timing circuit, wherein the clock adjustment circuit is configured to apply one or more of a clock skew adjustment, clock inversion or a margin adjustment in generating the launch clock or the capture clock.
22. The system of claim 17 , wherein the voltage regulator is configured to increase the supply voltage based on the output of the timing circuit.
23. The system of claim 17 , the output of the timing circuit is coupled to a clock generation circuitry to cause a change in system clock rate based on the output of the timing circuit.
24. The system of claim 17 , further including the semiconductor circuit, wherein the performance sensor is operable to provide the output of the timing circuit to the voltage regulator or to a clock generator in real time during an operation of the semiconductor circuit, and wherein the voltage regulator or the clock generator are configured to adjust one or both of the value of the supply voltage or a system clock rate based on the output of the timing circuit.