Dynamic temperature sensing cadence
An integrated circuit includes a plurality of temperature sensor circuits, placed in respective locations distributed across the integrated circuit, and a control circuit. Ones of the plurality of temperature sensor circuits may be configured to produce respective sets of temperature samples indicating an operating temperature of a respective region of the integrated circuit. The control circuit may be configured to sample, using a particular sample rate, respective temperature samples from a subset of the plurality of temperature sensor circuits. The control circuit may be further configured to determine a particular temperature estimate using one or more of the temperature samples and an operating mode of a functional circuit within the respective regions of the subset of temperature sensors. In response to a determination that the particular temperature estimate satisfies a threshold value, the control circuit may be configured to adjust the particular sample rate for subsequent temperature samples.
1 . An apparatus comprising:
an integrated circuit including:
a plurality of temperature sensor circuits placed in respective locations distributed across the integrated circuit, wherein ones of the plurality of temperature sensor circuits are configured to produce respective sets of temperature samples indicating an operating temperature of a respective region of the integrated circuit; and
a control circuit configured to:
sample, using a particular sample rate, respective temperature samples from a subset of the plurality of temperature sensor circuits;
determine a particular temperature estimate using one or more of the temperature samples;
adjust the particular temperature estimate based on an operating mode of a functional circuit within the respective regions of the subset of temperature sensors, wherein the operating mode includes one or more indications of an activity level of the functional circuit; and
in response to a determination that the particular temperature estimate satisfies a threshold value, adjust the particular sample rate for subsequent temperature samples.
2 . The apparatus of claim 1 , wherein to determine whether the particular temperature estimate satisfies the threshold value, the control circuit is configured to use the particular temperature estimate to access a particular entry in a sample-rate table to select an adjusted sample rate, wherein the sample-rate table includes a plurality of sample rates mapped to a corresponding plurality of temperature estimates.
3 . The apparatus of claim 2 , wherein the integrated circuit includes a plurality of sample-rate tables; and
wherein the control circuit is further configured to access a particular one of the plurality of sample-rate tables based on a type of the functional circuit that is within the respective regions of the subset of temperature sensor circuits.
4 . The apparatus of claim 1 , wherein the subset of the plurality of temperature sensor circuits is distributed among a plurality of functional circuits included within a particular processor core of a multicore processor included on the integrated circuit.
5 . The apparatus of claim 4 , wherein the particular temperature estimate is indicative of a temperature of the particular processor core.
6 . The apparatus of claim 5 , wherein the control circuit is further configured to:
sample, using a different sample rate, respective temperature samples from a different subset of the plurality of temperature sensor circuits; and
determine a different temperature estimate using one or more of the temperature samples of the different subset, wherein the different temperature estimate is indicative of a temperature of a different processor core.
7 . The apparatus of claim 1 , wherein to determine the particular temperature estimate, the control circuit is further configured to use a power estimate for the functional circuit within the respective regions, wherein the power estimate is based on a current workload of the functional circuit.
8 . The apparatus of claim 1 , wherein the control circuit is further configured to:
track increases in a series of temperature estimates to determine when to increase the particular sample rate; and
track decreases in the series of temperature estimates to determine when to decrease the particular sample rate.
9 . The apparatus of claim 1 , wherein to determine the particular temperature estimate, the control circuit is further configured to use a thermal conductivity value to estimate a difference between a given temperature sample and a temperature of the functional circuit in the respective regions.
10 . A method comprising:
sampling, using a particular sample rate, a subset of a plurality of temperature sensor circuits to generate a set of temperature samples, wherein the plurality of temperature sensor circuits is distributed across an integrated circuit;
determining, using the set of temperature samples a particular temperature estimate indicative of a temperature of a particular functional circuit included on the integrated circuit;
modifying the particular temperature estimate based on an operating mode of the particular functional circuit, wherein the operating mode includes one or more indications of an activity level of the particular functional circuit; and
determining, based on a comparison of the particular temperature estimate to a threshold value, whether to adjust a sample rate for subsequent samples.
11 . The method of claim 10 , further comprising determining, using the set of temperature samples and an operating mode of a different functional circuit on the integrated circuit, a different temperature estimate indicative of a temperature of the different functional circuit.
12 . The method of claim 11 , wherein determining the particular and different temperature estimates includes using respective physical locations of the particular and different functional circuits in relation to the respective physical locations of the subset of temperature sensor circuits.
13 . The method of claim 12 , wherein using the respective physical locations includes using a thermal conductivity value to estimate differences between a given temperature sample and the respective temperatures of the particular and different functional circuits.
14 . The method of claim 10 , wherein the subset of the plurality of temperature sensor circuits is distributed among a plurality of functional circuits included within a particular processor core of a multicore processor included on the integrated circuit.
15 . The method of claim 10 , wherein determining the particular temperature estimate includes using a power estimate for the particular functional circuit, wherein the power estimate is based on a current workload of the particular functional circuit.
16 . A system comprising:
an integrated circuit including:
a plurality of processor cores;
a plurality of temperature sensor circuits distributed among the processor cores; and
a control circuit; and
a management circuit configured to adjust an operating parameter of one or more of the processor cores using a temperature estimate received from the integrated circuit;
wherein the control circuit configured to:
collect temperature samples from a particular subset of the temperature sensor circuits using a first sample rate, wherein the particular subset includes temperature sensor circuits associated with a particular one of the processor cores;
determine a particular temperature estimate using the collected temperature samples from the particular subset of temperature sensor circuits;
adjust the particular temperature estimate based on an operating mode of the particular processor core, wherein the operating mode includes one or more indications of an activity level of the particular processor core;
send the particular temperature estimate and an identifier for the particular processor core to the management circuit; and
determine, based on a comparison of the particular temperature estimate to a threshold value, whether to select a second sample rate for collecting subsequent temperature samples.
17 . The system of claim 16 , wherein the control circuit is further configured to:
determine, using temperature samples collected from a different subset of temperature sensor circuits associated with a different one of the plurality of processor cores, a different temperature estimate indicative of a temperature of the different processor core; and
send the different temperature estimate and an identifier for the different processor core to the management circuit.
18 . The system of claim 17 , wherein the management circuit is further configured to:
select, using the particular temperature estimate, a particular set of operating parameters for the particular processor core; and
select, using the different temperature estimate, a different set of operating parameters for the different processor core.
19 . The system of claim 16 , wherein the control circuit is further configured to:
track increases in a first series of temperature samples from a first subset of temperature sensor circuits to determine when to increase a sample rate for the first subset of temperature sensor circuits; and
concurrently track decreases in a second series of temperature samples from a second subset of temperature sensor circuits to determine when to decrease a sample rate for the second subset of temperature sensor circuits.
20 . The system of claim 19 , wherein the control circuit is further configured to:
determine the sample rate for the first subset of temperature sensor circuits using a first sample-rate table; and
determine the sample rate for the second subset of temperature sensor circuits using a second sample-rate table, different from the first sample-rate table.