US5798918A
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US
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Performance-temperature optimization by modulating the switching factor of a circuit
Assignee: GlobalFoundries Inc
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Filing: 1996-04-29
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Granted: 1998-08-25
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Expires: 2016-04-29
Abstract
Abstract A system and method for modulating the switching factor of a circuit to control heating and which does not require modulation of the circuit's clock frequency. The switching factor refers to the fact that due to gating requirements, latency and data transfer characteristics, the rate at which a circuit's inputs are addressed is some fraction of the circuit clock frequency. Application can be made to many existing systems which incorporate single or multiple VLSI circuits such as superscalar microprocessors, parallel processors, DSPs, microcontrollers and MPEG decoders. A method for controlling a switching factor of a multi-functional unit processor includes the steps of: scheduling instructions stored in a memory for execution on each functional unit; generating a first temperature signal for a first functional unit and a second temperature signal for a second functional unit, each temperature signal being a function of a temperature associated with each functional unit; identifying the first functional unit and the second functional unit associated with each temperature signal, responsive to the generating step; comparing the first temperature signal with a first predetermined temperature threshold signal; generating a first temperature delay signal when the first temperature signal exceeds the first predetermined threshold, responsive to the comparison; and reducing the switching factor of the first functional unit according to the first temperature delay signal by delaying scheduling instructions for execution on the first functional unit. Further reduction in power dissipation may be achieved by using thermal feedback to cooperatively vary the voltage and frequency of a circuit.
Inventors
- 👤 Christos John Georgiou
- 👤 Edward Scott Kirkpatrick
- 👤 Thor Arne Larsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:57
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/30; G06F9/38; G06F9/3836; G05; G05B; G05B13/00; G05B13/02; G05B13/0205; G05B13/024
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
104 words
A method for varying a switching factor (S) of a clocked circuit operating at a frequency (f) and including one or more functional units adapted for performing one or more functions, said method comprising the steps of: generating a temperature signal which is a function of a temperature associated with the circuit; comparing the temperature signal with a predetermined temperature threshold signal; and varying the switching factor of a functional unit by varying processing of one of instructions and data on the functional unit, wherein the functional unit dissipates power at a fraction (1/S) of circuit clock cycles, responsive to said step of comparing.
Claim 2
Independent Claim
104 words
A method for varying a switching factor (S) of a clocked circuit operating at a frequency (f) and including one or more functional units adapted for performing one or more functions, said method comprising the steps of: generating a temperature signal which is a function of a temperature associated with the circuit; comparing the temperature signal with a predetermined temperature threshold signal; and varying the switching factor of a functional unit by varying processing of one of instructions and data on the functional unit, wherein the functional unit dissipates power at a fraction (1/S) of circuit clock cycles, responsive to said step of comparing.
Claim 3
Dependent Claim
43 words
A method as claimed in claim 1, further comprising the steps of generating a temperature delay signal, responsive to said comparing step, wherein said step of varying the switching factor comprises reducing the switching factor as a function of the temperature delay signal.
Claim 4
Dependent Claim
53 words
A method as claimed in claim 1, further comprising the steps of: generating a second temperature signal subsequent to the temperature signal; and comparing the second temperature signal with the predetermined temperature threshold signal; wherein said step of varying the switching factor is responsive to said step of comparing the second temperature signal.
Claim 5
Dependent Claim
72 words
A method as claimed in claim 1, in a data processing system with a plurality of circuits including a first functional unit and a second functional unit, further comprising the steps of: generating the temperature signal for each functional unit and identifying the one of the first and second functional unit associated with the temperature signal; and varying the switching factor of the first functional unit, responsive to said step of comparing.
Claim 6
Dependent Claim
40 words
A method as claimed in claim 4, further comprising the steps of scheduling one of an instruction and data for processing on the second functional unit, responsive to said step of vary the switching factor of the first functional unit.
Claim 7
Independent Claim
13 words
A method as claimed 1 wherein said step of generating is done periodically.
Claim 8
Dependent Claim
45 words
A method as claimed in claim 1 further comprising the steps of: converting the temperature signal to a delay signal which includes a value, responsive to said step of generating; and wherein said step of varying the switching factor is a function of the value.
Claim 9
Dependent Claim
56 words
A method as claimed in claim 1, in a data processing system having a superscalar architecture including the one or more functional units, wherein said varying step further comprises the step of scheduling one of instructions and data stored in a memory for processing on the one or more functional units responsive to the temperature signal.
Claim 10
Dependent Claim
53 words
A method as claimed in claim 8 wherein the temperature signal is generated for the one or more functional units, said method comprising the steps of identifying the functional unit associated with the temperature signal; wherein said varying step comprises varying the switching factor of the functional unit responsive to said identifying step.
Claim 11
Dependent Claim
63 words
A method as claimed in claim 1 wherein the one or more functional units is selected from the group consisting of: a superscalar microprocessor; a fixed-point unit, a floating point unit, a load/store unit, and a branch unit found in general purpose and superscalar microprocessors; a closely-coupled parallel processor; a distributed parallel processor; a microcontroller; an MPEG decoder; and a digital signal processor.
Claim 12
Dependent Claim
24 words
A method as claimed in claim 1, further comprising the step of regulating the voltage to the circuit, responsive to said step of comparing.
Claim 13
Dependent Claim
48 words
A method as claimed in claim 11, wherein said step of regulating the voltage to the circuit, comprises the steps of generating logic signals to control current sources to an adjustable voltage regulator coupled to the circuit; and varying the voltage regulator output according to the logic signals.
Claim 14
Dependent Claim
51 words
A method as claimed in claim 1 wherein the functional unit is selected from the group consisting of: a superscalar microprocessor; a fixed-point unit, a floating point unit, a load/store unit, and a branch unit found in general purpose and superscalar microprocessors; a closely-coupled parallel processor; a microcontroller; an MPEG decoder.
Claim 15
Independent Claim
191 words
A method of using thermal feedback to modulate the switching factor of a first functional unit and a second functional unit in a data processing system, the method comprising the steps of: scheduling instructions stored in a memory for execution on each functional unit; generating a first temperature signal for the first functional unit and a second temperature signal for the second functional unit, each temperature signal being a function of a temperature associated with said each functional unit; identifying the first functional unit and the second functional unit associated with said each temperature signal, responsive to said generating step; comparing the first temperature signal with a first predetermined temperature threshold signal; generating a first temperature delay signal, responsive to said comparing step; reducing a switching factor of the first functional unit to control heating as a function of the first temperature delay signal by delaying said step of scheduling instructions for execution on the first functional unit, wherein the switching factor is the fraction of clock cycles that each functional unit is dissipating power, and rescheduling said instructions for execution on the first functional unit on said second functional unit.
Claim 16
Independent Claim
191 words
A method of using thermal feedback to modulate the switching factor of a first functional unit and a second functional unit in a data processing system, the method comprising the steps of: scheduling instructions stored in a memory for execution on each functional unit; generating a first temperature signal for the first functional unit and a second temperature signal for the second functional unit, each temperature signal being a function of a temperature associated with said each functional unit; identifying the first functional unit and the second functional unit associated with said each temperature signal, responsive to said generating step; comparing the first temperature signal with a first predetermined temperature threshold signal; generating a first temperature delay signal, responsive to said comparing step; reducing a switching factor of the first functional unit to control heating as a function of the first temperature delay signal by delaying said step of scheduling instructions for execution on the first functional unit, wherein the switching factor is the fraction of clock cycles that each functional unit is dissipating power, and rescheduling said instructions for execution on the first functional unit on said second functional unit.
Claim 17
Dependent Claim
24 words
A method as claimed in claim 14, further comprising the step of regulating the voltage to the circuit, responsive to said step of comparing.
Claim 18
Dependent Claim
43 words
A method as claimed in claim 15, wherein said step of regulating the voltage to the circuit, comprises the step of generating logic signals to control current sources to an input of an adjustable voltage regulator having an output coupled to the circuit.
Claim 19
Dependent Claim
41 words
A method as claimed in claim 16, wherein said step of reducing further comprises the steps of scheduling one of instructions and data for processing on the second functional unit, responsive to the first functional unit generating the temperature delay signal.
Claim 20
Independent Claim
118 words
A system for controlling a switching factor of a functional unit included in a data processing system to control heating, said system comprising: a temperature signal means for generating a temperature signal which is a function of a temperature associated with the functional unit; and a switching factor means for varying the switching factor of the functional unit, coupled to said temperature signal means, responsive to the temperature signal, wherein the switching factor is a fraction of clock cycles that the functional unit is dissipating power; said switching factor means including scheduler means for scheduling one of an instruction and data for processing on the functional unit, responsive to said temperature signal means for generating the temperature signal.
Claim 21
Independent Claim
118 words
A system for controlling a switching factor of a functional unit included in a data processing system to control heating, said system comprising: a temperature signal means for generating a temperature signal which is a function of a temperature associated with the functional unit; and a switching factor means for varying the switching factor of the functional unit, coupled to said temperature signal means, responsive to the temperature signal, wherein the switching factor is a fraction of clock cycles that the functional unit is dissipating power; said switching factor means including scheduler means for scheduling one of an instruction and data for processing on the functional unit, responsive to said temperature signal means for generating the temperature signal.
Claim 22
Dependent Claim
92 words
A system as claimed in claim 18 wherein said switching factor means further comprises: a comparator means for comparing the temperature signal with a predetermined temperature threshold signal; a temperature delay signal means for generating a temperature delay signal when the temperature signal exceeds the predetermined threshold, the temperature delay signal having a magnitude representing an amount by which the temperature signal exceeds the predetermined threshold, responsive to said comparing step; and wherein said switching factor means includes means for reducing the switching factor as a function of the temperature delay signal.
Claim 23
Dependent Claim
52 words
A system as claimed in claim 19 wherein said temperature signal means includes means for generating a second temperature; and wherein said for switching factor means includes means for increasing the switching factor when a second temperature signal received subsequent to the temperature signal does not exceed the predetermined temperature threshold signal.
Claim 24
Dependent Claim
73 words
A system as claimed in claim 18, wherein the data processing system comprises a first functional unit and a second functional unit, and wherein said temperature signal means further comprises means for generating the temperature signal for each functional unit; and a functional unit identifier means, coupled to each functional unit and to said switching factor means, for identifying the one of the first and second functional unit associated with the temperature signal.
Claim 25
Dependent Claim
42 words
A system as claimed in claim 18 wherein said switching factor means further comprises: a scheduler means for scheduling one of an instruction and data for processing on the functional unit, responsive to said temperature signal means for generating the temperature signal.
Claim 26
Dependent Claim
20 words
A system as claimed in claim 18 wherein said temperature signal means includes means for generating the temperature signal periodically.
Claim 27
Dependent Claim
41 words
A system as claimed in claim 18 further comprising: a decoder means for converting the temperature signal to a delay signal having a value, responsive to said step of generating; and wherein said switching factor means is responsive to the value.
Claim 28
Dependent Claim
41 words
A system as claimed in claim 18, wherein the data processing system comprises a plurality of functional units, and wherein the scheduler means for scheduling one of instructions and data for processing on the functional units responsive to the temperature signal.
Claim 29
Dependent Claim
73 words
A system as claimed in claim 25 wherein said temperature signal means is coupled to each functional unit, said system comprising: a functional unit identifier means, coupled to each functional unit and to said switching factor means, for identifying said each functional unit associated with the temperature signal; and wherein said switching factor means includes means for varying the switching factor of said each functional unit responsive to said functional unit identifier means.
Claim 30
Dependent Claim
16 words
A system as claimed in claim 25 wherein the data processing system includes a superscalar microprocessor.
Claim 31
Dependent Claim
17 words
A system as claimed in claim 25 wherein the data processing system includes a distributed parallel processor.
Claim 32
Dependent Claim
17 words
A system as claimed in claim 25 wherein the data processing system includes a digital signal processor.
Claim 33
Dependent Claim
28 words
A system as claimed in claim 18, wherein a thermal sensor is integral with the functional unit, and wherein the temperature signal is generated by the thermal sensor.
Claim 34
Dependent Claim
15 words
The system as claimed in claim 30 wherein the thermal sensor is a ring oscillator.
Claim 35
Independent Claim
239 words
A system for controlling the switching factor of a data processing system including a first functional unit and a second functional unit, comprising: a scheduler means, coupled to each functional unit, for scheduling one of instructions and data for processing on said each functional unit; a temperature signal means, coupled to each functional unit and to the scheduler means, for generating a first temperature signal which is a function of a temperature associated with the first functional unit and a second temperature signal which is a function of a temperature associated with the second functional unit; functional unit identifier means, coupled to the temperature signal means and to the scheduler means, for identifying the first functional unit and the second functional unit associated with said each temperature signal, responsive to said generating step; a comparator means, coupled to the temperature signal means, for comparing the first temperature signal with a first predetermined temperature threshold signal, and for generating a first temperature delay signal when the first temperature signal exceeds the first predetermined threshold, responsive to the comparator means; and said scheduler means including a switching factor means for reducing the switching factor of the first functional unit as a function of the first temperature delay signal by delaying said scheduling one of instructions and data for processing on said each functional unit, wherein the switching factor is the fraction of clock cycles that the functional unit is dissipating power.
Claim 36
Independent Claim
239 words
A system for controlling the switching factor of a data processing system including a first functional unit and a second functional unit, comprising: a scheduler means, coupled to each functional unit, for scheduling one of instructions and data for processing on said each functional unit; a temperature signal means, coupled to each functional unit and to the scheduler means, for generating a first temperature signal which is a function of a temperature associated with the first functional unit and a second temperature signal which is a function of a temperature associated with the second functional unit; functional unit identifier means, coupled to the temperature signal means and to the scheduler means, for identifying the first functional unit and the second functional unit associated with said each temperature signal, responsive to said generating step; a comparator means, coupled to the temperature signal means, for comparing the first temperature signal with a first predetermined temperature threshold signal, and for generating a first temperature delay signal when the first temperature signal exceeds the first predetermined threshold, responsive to the comparator means; and said scheduler means including a switching factor means for reducing the switching factor of the first functional unit as a function of the first temperature delay signal by delaying said scheduling one of instructions and data for processing on said each functional unit, wherein the switching factor is the fraction of clock cycles that the functional unit is dissipating power.
Claim 37
Dependent Claim
40 words
A system as claimed in claim 32, wherein said scheduler means further comprises means for scheduling one of said instructions and data for processing on the second functional unit, responsive to the first functional unit generating the temperature delay signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-24 | 2002-02-23 | 2002-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-24 | 2006-02-23 | 2006-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-24 | 2010-02-23 | 2010-08-25 | $7700.00 | Window Closed / Lapsed |