Patent EP0426410B1 successfully refreshed from Google Patents.
EP0426410B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Real-time power conservation for portable computers
Assignee: Texas Instruments Inc
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Filing: 1990-10-29
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Granted: 1996-06-19
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Expires: 2010-10-29
Abstract
No abstract record available.
Inventors
- 👤 Lavaughn F. Jr. Watts
- 👤 Steven J. Wallace
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 15:30
CPC Classifications
G; G06; G06F; G06F15/00; G06F15/02; G06F1/00; G06F1/26; G06F1/32; G06F1/3203; G06F1/3234; G06F1/324; G06F1/16; G06F1/20; G06F1/206; Y; Y02; Y02D; Y02D10/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
129 words
A method for implementing a real-time power conservation mode in a computer having a central processing unit (CPU), comprising the sequential steps of: determining in real time the level of CPU activity by detecting periods of activity (70) and inactivity (60) of said CPU; deciding from said level of CPU activity whether it is available for power conservation; if said CPU is available for power conservation, causing a hardware selector (500,510,520,530) to reduce the clock rate below the current clock rate or stop the clock provided to said CPU (280); maintaining the clock stopped or at the reduced rate until an interrupt occurs (320), and causing said hardware selector to restore the clock rate provided to said CPU to said current clock rate in response to said interrupt (330).
Claim 2
Dependent Claim
97 words
A method according to claim 1, wherein said step of causing a hardware selector to reduce the clock rate provided to the CPU below the current clock rate or stop the clock provided to said CPU (280), further comprises the step of: applying a power conservation CPU command via a communication line to said hardware selector; said hardware selector being arranged to select a power conservation clock in response to said power conservation CPU command, and to apply pulses from said power conservation clock to said CPU thereby to place said CPU in a power conservation mode.
Claim 3
Dependent Claim
91 words
A method according to claim 1 or claim 2, wherein said step of causing said hardware selector to restore the clock rate provided to said CPU to said current clock rate, further comprises the step of: applying a wake CPU command via a communication line to said hardware selector; said hardware selector being caused to select said clock having said current clock rate in response to said wake CPU command, and to apply clock pulses from said clock having said current clock rate to said CPU thereby to wake said CPU.
Claim 4
Dependent Claim
70 words
A method according to claim 1, claim 2 or claim 3 wherein said step of determining the level of CPU activity further comprises the steps of: ascertaining whether said CPU is already in a power conservation mode; and if not, determining whether there are interrupts available to restore the clock rate provided to said CPU to said current clock rate before said CPU is put into a power conservation mode.
Claim 5
Dependent Claim
60 words
A method according to claim 1, wherein said step of causing a hardware selector to reduce the clock rate below the current clock rate or stop the clock provided to the CPU, further comprises the steps of: determining whether there has been an increase in CPU activity; and adjusting a rest interval of said CPU according to that determination (20,30).
Claim 6
Dependent Claim
18 words
A method according to claim 1, wherein said interrupt is generated by a periodic activity within the computer.
Claim 7
Independent Claim
42 words
A method according to any one of claims 1 to 6 including selecting said current clock rate from either a first clock speed provided by a first high speed clock or a second clock speed provided by a second high speed clock.
Claim 8
Dependent Claim
53 words
A method according to claim 7, wherein said step of deciding whether said CPU is available for power conservation further comprises the steps of: if said CPU is available for power conservation, determining the current clock rate (260) of said CPU; and saving a value representative of said determined current clock rate (270).
Claim 9
Dependent Claim
50 words
A method according to claim 8, wherein the step of causing said hardware selector to restore said determined current clock rate to said CPU further comprises the steps of: retrieving said saved value; and setting the clock rate of said CPU to the rate represented by the retrieved value (330).
Claim 10
Independent Claim
62 words
A method according to any one of claims 1 to 9, wherein before the step of determining the level of CPU activity, control is accepted from the operating system of the CPU, and after the step of causing said hardware selector to restore the clock rate provided to said CPU to said current clock rate, control is returned to the operating system.
Claim 11
Dependent Claim
37 words
A method according to claim 10, wherein if the decision from determining the level of CPU activity of said CPU is that said CPU is not available for power conservation then returning control to the operating system.
Claim 12
Independent Claim
177 words
An apparatus for real time power conservation in a computer having a central processing unit (CPU), comprising : a first clock oscillator (550) for providing pulses at a first rate; a second clock oscillator (540) for providing pulses at a second rate, slower than said first rate; and a hardware selector (500, 510, 520, 530) for selecting pulses from said first oscillator or from said second oscillator, said hardware selector being arranged to apply the selected pulses as clock signals to said CPU; the apparatus being characterized by further comprising : a CPU activity detector (10) for determining in real time the level of CPU activity by detecting periods of activity and inactivity of said CPU and providing an indication of that level of CPU activity; and a CPU sleep manager (20,30) adapted to receive the indication of the level of CPU activity from said CPU activity detector, and to apply a signal to said hardware selector designating which pulses said hardware selector should select to apply clock signals to said CPU, according to said received indication.
Claim 13
Dependent Claim
20 words
An apparatus according to claim 12, wherein said CPU activity detector and said CPU sleep manager reside within said CPU.
Claim 14
Dependent Claim
137 words
An apparatus according to claim 12 or claim 13, wherein said CPU sleep manager further comprises: an adjustor (20 ,30) responsive to said indication representing the current detected CPU activity level for lengthening a CPU rest period when said current detected CPU activity level has decreased or for shortening said CPU rest period when said current detected CPU activity level has increased; a clock rate keeper for determining a current clock rate for said CPU, for saving a value equal to said current clock rate while said CPU is receiving clock pulses at another rate for power conservation, as well as for retrieving said saved value when said CPU is to return to normal operation; and a pulse generator for generating a pulse for designating to said hardware selector which oscillator pulses said hardware selector should select.
References Cited (Backward Citations)
No citation records indexed.
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