Abstract:
Disclosed is an apparatus and method of power-saving and wake-up, which is not only used to reduce the power consumption of a system of electronic equipment, but also allow the system to immediately return to normal operation according to the requirement. The apparatus for power-saving and wake-up includes a first detector, a second detector, a decoder and a third detector. The method for power-saving and wake-up includes detecting a cable signal, a clock pair signal and a differential pair signal. When one of the detected signals is unusual, the system soon turns off the unusual channel power and implement the procedures for power saving and operates under the power saving mode, which can realize the effect of power saving and low power consumption. The method for power-saving and wake-up includes detecting the cable signal, the toggling and frequency of the clock signal and the synchronizing signals of the system.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present invention is a CIP application of the parent application Ser. No. 11/259,541, filed on Oct. 25, 2005. “Method for Power Management In A Displays” which is hereby incorporated herein in its entirety by reference. 
     
    
     FIELD OF TE INVENTION 
       [0002]    The present invention relates to the field of power management, particularly to the apparatus and method for power-saving and wake-up of a receiver. 
       BACKGROUND OF THE INVENTION 
       [0003]    If a display device (for examples: CRT display or LCD display) has a power management function, the power consumption of the display device can be reduced and the components of the display device can be protected. The display power management signaling (DPMS) is a common standard for the display device. In the DPMS standard, the computer will selectively provide at least one of video signals (for example: a vertical synchronization signal, VSYNC, and a horizontal synchronization signal, HSYNC) to the display device, and the display device will determine to perform the power management function when the computer transfer no video signal to the display device. Generally speaking, both the computer and the display device have two operation modes (i.e., a normal mode and a power-saving mode). When the computer operates in the normal mode, the computer will transfer the video signal into the display device through a plurality of video charnels of a video interface, and the display device will display the video signal in the normal mode. When the computer enters the power-saving mode (for example: a user doesn&#39;t use this computer for a predetermined time interval), the computer will not provide the video signal to the display device and the display device will simultaneously enter the power-saving mode. 
         [0004]    In prior technology, there are two conventional methods for power management of the display device. The first conventional method: the display device will turn off its power supply when it enters the power-saving mode. That is, the conventional display device disables (i.e. turns off) all video channels in the power-saving mode. The second conventional method: the display device will keep enabling (i.e. turning on) one of the video channels of the video interface and disabling other video channels in the power-saving mode. Generally speaking, the conventional display device will only keep enabling a blue channel when operating in the power-saving mode. The conventional display device will detect whether the video signal is input to the display device through the enabled video channel. When the video signal of the enabled video channel is detected, other disabled video channels will be enabled and the conventional display device will return to the normal mode. In the second conventional method, although the display device can respond to external changes in the power-saving mode, the enabled video channel needs to be kept enabled all the time and the power consumption of the display device can not be fully reduced. 
         [0005]    Please refer to  FIG. 1 , which is a schematic diagram showing a conventional signal receiving equipment. The signal receiving equipment has a transmitter  11 , a receiver  12  and a signal transmission line  13 . The transmitter  11  also has a current source  111  and a pair of switches D and D′. Coupled to a power supply AVcc, the receiver  12  also has a receiver circuit (i.e. differential amplifier) and a pair of resistors RT and RT′. The resistors RT and RT′ respectively connect to the transmission line  13 . 
         [0006]    In this conventional structure, if the receiver  12  enters into the power-saving mode (the differential amplifier is disabled), the power supply AVcc of the receiver  12  will still flow through the pair of resistors RT and RT′ and the transmission line  13  and reach the grounding of the transmitter  11 ; in other words, even if the receiver  12  has entered the power-saving mode, the entire equipment will always provide current to the transmission line  13 . The receiver  12  still consumes the power even though the system operates in the power-saving mode. 
         [0007]    To solve the above drawbacks in the prior art, the applicant uses a detection function to turn off the partial circuit of the receiver for reducing the power consumption. The applicant also utilizes a detected signal generated from a detection circuit to activate the receiver to operate in the normal function. Therefore, the present invention “apparatus and method for power-saving and wake-up” is to overcome the above-mentioned shortcomings of conventional means. 
         [0008]    In order to eliminate the drawbacks of the conventional techniques, the new concepts and the solutions are proposed in the present invention so as to solve the above-mentioned problems. The present invention is described below. 
       SUMMARY OF THE INVENTION 
       [0009]    The purpose of the present invention is to provide an apparatus and method for power-saving and wake-up to reduce the power consumption of a signal receiving device. Besides, the present can instantly activate a circuit by monitoring signals to satisfy the requirement of the user. 
         [0010]    In accordance with one aspect of the present invention, a method used in a power-saving mode of a receiver, comprising the steps of: (a) detecting whether a first signal is normal in the power-saving mode and maintaining in the power-saving mode when the first signal is abnormal; and (b) detecting whether a second signal is normal when the first signal is normal in the power-saving mode, and maintaining the receiver in the power-saving mode when the second signal is abnormal. 
         [0011]    Preferably, the receiver further comprises a first and a second channels and a power supply, and each of the steps (a) and (b) further comprises the steps of: detecting at least one signal from one of the first and the second channels and producing a control signal according to a detected result; and deciding whether to disconnect a connection between the power supply and at least one of the first and second channels according to the control signal so as to avoid a current flowing through the at least one of the first and second channels. 
         [0012]    Preferably, the steps (a) and (b) are respectively performed by a step (a1) of activating a detecting function of the first channel and a step (b1) of activating a detecting function of the second channel. 
         [0013]    Preferably, the receiver maintains in the power-saving mode when the first signal is abnormal. 
         [0014]    Preferably, the first and the second channels respectively transmit a clock signal and a data signal. 
         [0015]    Preferably, the first signal is one of a cable signal and a clock signal, and the second signal is one of the clock signal and a data signal. 
         [0016]    Preferably, the receiver operates in a normal mode if the second signal is normal. 
         [0017]    Preferably, the receiver has a third channel, and the method further comprises the steps of: detecting whether a third signal from the third channel is normal in the power-saving mode when the second signal is normal, wherein the receiver maintains the power-saving mode when the third signal is abnormal; and operating the receiver in the normal mode when the third signal is normal. 
         [0018]    In accordance with another aspect of the present invention, A receiver is provided, comprising: at least one of receiving units, coupled to at least one of channels, respectively, receiving an input signal from the at least one of the channels; a control circuit detecting a specific one of the input signal from the at least one of the channels, producing a control signal according to a result of the detection, and having plural routes, each of which corresponds to the specific one of the input signal. 
         [0019]    Preferably, the receiver further comprises at least one channel having the specific one of the input signal, a power supply, a receiver circuit receiving the specific one of the input signal from the at least one channel and having a control switch configured between the power supply and the at least one channel and deciding whether to disconnect a connection between the power supply and the at least one channel according to the control signal, and a following circuit receiving and processing an output signal from the receiver circuit. 
         [0020]    Preferably, the receiver further comprises at least one of a digital visual interface and a high definition multimedia interface. 
         [0021]    Preferably, the at least one channel has a first and a second channels respectively transmitting a clock signal and a data signal. 
         [0022]    Preferably, the data signal is any one of three pairs of red, green and blue data signals. 
         [0023]    Preferably, the at least one channel is used to transmit a clock signal, and the control circuit comprises a detector detecting at least one of toggling and frequency of the clock signal. 
         [0024]    Preferably, the at least one channel is used to transmit a data signal, and the control circuit comprises a decoder decoding a data signal from the at least one channel and a first detector detecting the decoded data signal. 
         [0025]    In accordance with another aspect of the present invention, a method used in a signal receiving device is provided. The method for a receiver coupling to at least one channel and having a power supply, comprising the steps of: detecting a specific one signal from the at least one channel and generating a control signal accordingly; and deciding whether to disconnect a connection between the power supply and the at least one channel according to the control signal so as to avoid a current flowing through the at least one channel when the receiver operates in a power-saving mode. 
         [0026]    Preferably, the at least one channel comprises a first channel and a second channel having plural decoded data signals, and the method further comprises: detecting at least one of toggling and frequency of the clock signal of the first channel; detecting a specific one of the plural decoded data signals; and wherein the receiver turns off the first and the second channels when the detected specific decoded data signal is abnormal, and operates in a power-saving mode. 
         [0027]    Preferably the plural decoded data signals comprise a horizontal synchronization signal, a vertical synchronization signal and a data enable signal. 
         [0028]    Preferably, the at least one channel comprises a first and a second channels, the receiver further comprises a control switch deciding whether to disconnect a connection between the power supply and at least one of the first channel and the second channel according to the control signal, and the first channel and the second channel respectively transmit a clock signal and a data signal. 
         [0029]    In sum, the present invention not only realizes the reduction of power consumption, but also improves the implementation of power-saving and wake-up for a signal receiving device. 
         [0030]    The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed descriptions and accompanying drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  is a schematic diagram showing a conventional signal receiving equipment. 
           [0032]      FIG. 2  is a simplified block diagram showing an apparatus for power-saving and wake-up of a signal receiving device of the present invention. 
           [0033]      FIG. 3  ( a ) is the block diagram showing an apparatus for power-saving and wake-up of a clock channel of the present invention. 
           [0034]      FIG. 3  ( b ) is the block diagram showing an apparatus for power-saving and wake-up of a data channel of the present invention. 
           [0035]      FIG. 4  illustrates a flow chart the method for power-saving and wake-up in a signal receiving device according to an embodiment of the present invention. 
           [0036]      FIG. 5  illustrates a flow chart the method for power-saving and wake-up in a signal receiving device according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for the purposes of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed. 
         [0038]    Please refer to  FIG. 2 , which is a simplified block diagram showing an apparatus for power-saving and wake-up of a signal receiving device of the present invention. The signal receiving device coupled to a power supply AVcc includes a receiver  20 , a control circuit  21  and a next circuit  22 . The receiver  20  further includes a pair of resistors  201 , a pair of switches  202  and a differential amplifier  203 . The receiver  20  receives an input signal S IN  from the transmitter  11 . Then, the input signal S IN  is processing by the differential amplifier  203  and becomes an output signal S OUT . The next circuit  22  receives the output signal S OUT  for the following treatment. At the same time, the control circuit  21  also receives the output signal S OUT , detects whether the output signal S OUT  is normal or not and thereby outputs a detected signal. When the detected signal presents that the output signal S OUT  is abnormal, the control circuit  21  outputs a control signal (to enable/disable the other circuits), triggering the pair of switches  202  off (open). Thus, the power AVcc of the receiver  20  is unable to follow through the pair of resistors RT and RT′ and the transmission line  13  and be lead to the grounding of the transmitter  11 . In other words, the current of the signal receiving device will not flow into the transmission line  13 , which allows the receiver of the related channel no longer consuming the power (that is, entering into the power-saving mode). One skilled in the art should easily know that the pair of the switches  202  and the amplifier  203  can simultaneously be controlled by control signals, or respectively controlled by other circuits. In a power-saving mode, the present invention will activate a detection function after each predetermined interval (adjustable). In an embodiment of activating the detection function is that the control circuit  21  simultaneously controls the pair of switches  202  to be a conduction state (ON) and controls the control amplifier  24  to be an enabling state, and detects whether the input signal S IN  is normal or not, so as to decide whether the other circuit (e.g. the next circuit) of the related channel or/and other channels in other circuits activates a detection function or enters into a normal operating mode. 
         [0039]    In another embodiment, the pair of resistors  201  and the pair of switches  202  can be implemented by a pair of transistors. In a normal mode and a detection function being activated, the gate voltage of the transistors can be controlled to provide impedance. In a power-saving mode, the pair of transistors is implemented as a pair of switches. Therefore, the power supply AVcc of the receiver  20  is not connected to the transmission line  13 . Moreover, owing to the type or character of the input signal S IN  changed based on different interface standards, the implementing configuration of the control circuit  21  of the present invention will be changed to different forms according to the different types or formats of the input signal S IN . In this specification, only a clock signal and a data signal are used for the description. 
         [0040]    When the input signal S IN  is a clock signal, please refer to  FIG. 3  ( a ), which is the block diagram showing an apparatus for power-saving and wake-up of a clock channel of the present invention. In this embodiment, the control circuit  21  also includes a first detector  211  and a second detector  212 . The receiver  20  receives a clock signal S IN  (clock) from transmitter  11 . Then, the clock signal S IN  (clock) is processing by the differential amplifier  203  and becomes an output signal S OUT . The output signal S OUT  is respectively transmitted to three paths. One output signal S OUT  is transmitted to the next circuit  22  for the following treatment. Another output signal S OUT  is sent to a first detector  211  to detect a toggling of the output signal S OUT . Another output signal S OUT  is sent to a second detector  212  to detect a frequency of the output signal S OUT  according to a reference clock. The control circuit  21  outputs a control signal (enable/disable signal), controlling the switch  23  open or close according to the detection result. Thus, there is no more power consumption in the clock channel (i.e. entering a power-saving mode). In another embodiment, only one of the toggling and frequency of the clock signal is detected, and output the detected signal according to the detection result. That is, the first detector  211  or the second detector  212  can be omitted. 
         [0041]    When the input signal S IN  is a data signal, please refer to  FIG. 3  ( b ), which is the block diagram showing an apparatus for power-saving and wake-up of a data channel of the present invention. In this embodiment, the control circuit  31  includes a decoder  311  and a third detector  312 . The receiver  30  receives an encoded data signal S IN  (R/G/B) from transmitter  11 . Then, the clock signal S IN  (R/G/B) is processing by the amplifier  303  and becomes an output signal S OUT  transmitted to the decoder  311 . The decoded signal is sent to the third detector  312  to detect whether at least one of a horizontal synchronization signal (HS), a vertical synchronization signal (VS), or a data enable signal (DE) is normal, and thereby produces the detection result. The control circuit  31  outputs a control signal (enable or disable signal) to control the pair of switches  302  open or close according to the detection result. Therefore, the data channel no longer consumes the power (that is, entering a power-saving mode). 
         [0042]    When the input signal S IN  includes a clock signal and a data signal, the receiver includes a clock channel receiver  20  and at least one data channel receiver  30 . In an embodiment, the control circuit  21  of the clock channel receiver  20  respectively or simultaneously controls all the enablement (normal mode) or disablement (power-saving mode) of the channels. In Another embodiment, the control circuit  31  of the clock channel receiver  30  respectively or simultaneously controls all the enablement (normal mode) or disablement (power-saving mode) of the channels. In Another embodiment, the control circuit ( 21 ,  31 ) of each channel receiver ( 20 ,  30 ) respectively controls all the enablement (normal mode) or disablement (power-saving mode) of each channel. 
         [0043]    Accordingly, the enabling and disabling actions of the above-mentioned clock enable signal and/or R/G/B data enable signal can be reached by one technique of the software control or hardware or both software and hardware by one skilled in the art. 
         [0044]    Please refer to  FIG. 4 , which is a flow chart the method for power-saving and wake-up in a signal receiving device according to an embodiment of the present invention.  FIG. 4  is illustrated based on the fact that the input signal S IN  includes a clock signal and a data signal, and the description is also based on the examples that each of the channels is respectively controlled: first of all, when operating in a normal mode, the system turns on a clock enable signal and R/G/B enable signals and turns on R/G/B receiver power (step  40 ). Then, the system detects the steps: whether or not a toggling of the clock signal is abnormal, whether or not HS/VS/DE (horizontal sync, vertical sync and data enable) of plural data signals are abnormal, or whether the cable signal is abnormal (i.e. whether the cable  13  is connected to the receiver  20 ) (step  41 ). When the signals are all normal, the system maintains operating in the normal mode. When any one of signals is abnormal, the system turns off (OPEN) the pair of switches ( 202 , 302 ) and let each channel enter power-saving mode (step  42 ). At this moment, the power AVcc of each receiver ( 20   30 ) is unable to flow through the pair of resistors RT and RT′ and the transmission line  13  and be lead to the grounding of the transmitter  11 . The receivers of each channel no longer consume any power (that is, entering into the power-saving mode). 
         [0045]    Accordingly, in the operation of power-saving mode, after an adjustable period of time, the system detects whether the cable signal is normal (step  43 ). When the signal is abnormal, the system maintains operates in the power-saving mode. When the signal is normal, after an adjustable period of time (step  44 ), the system turns on the clock channel to receive and detect the clock signal (step  45 ). 
         [0046]    Then, the system detects whether the toggling of the clock signal is normal (step  46 ). The system maintains operating in the power-saving mode when the signal is abnormal. When the toggling of the clock signal is normal, the system detects whether the frequency of the clock signal is normal (step  47 ). 
         [0047]    Accordingly, the system maintains operating in the power-saving mode when the frequency of the clock signal is abnormal. The system turns on a blue channel and a blue data receiver power when the frequency of the clock signal is normal (step  48 ). 
         [0048]    Then, the system detected whether the HS/VS/DE (horizontal sync, vertical sync and data enable) of blue channel are normal (step  49 ). When the signals are abnormal, the system maintains operating in the power-saving mode. When the signals are normal, the system enters into the operation in the normal mode (step  40 ). 
         [0049]    There are several ways to wake up, for example: steps  44 ˜ 49  can be omitted (only determine whether the cable signal is normal), or steps  47 ˜ 49  can be omitted (only determine whether the cable signal and clock signal are normal), or steps  45 ˜ 47  can be omitted (only determine whether the cable signal and HS/VS/DE signals are normal). One skilled in the art can easily complete all kinds of deformations. 
         [0050]    Please refer to  FIG. 5 , which illustrates a flow chart of the method for power-saving and wake-up in a signal receiving device according to an embodiment the present invention. First of all, when operating in a normal mode, the system turns on a clock enable signal and R/G/B enable signals and turns on R/G/B receiver power (step  50 ). Then, the system detects the steps: whether or not a cable signal, a clock signal, HS/VS/DE (horizontal sync, vertical sync and data enable) plural data signals are abnormal (step  51 ). When the signals are normal, the system maintains operating in the normal mode. When any one of the signals is abnormal, the system turns off a clock channel, R/G/B channel and enters power-saving mode (step  52 ). 
         [0051]    after an adjustable period of time, the system detects whether the cable signal is normal (step  53 ). When the signal is abnormal, the system maintains operating in the power-saving mode. When the signal is normal, after an adjustable period of time (step  54 ), the detection function of the clock channel is enabled and the system turns on the clock channel (step  55 ). 
         [0052]    Then, the system detects whether the toggling of clock signal is normal (step  56 ). The system maintains operating in the power-saving mode when the signal is abnormal. When the toggling of the clock signal is normal, the system detects whether frequency of the clock signal is normal (step  57 ). 
         [0053]    Accordingly, the system maintains operating in the power-saving mode when the frequency of clock signal is abnormal. The system turns on the clock/R/G/B channels when the signal is normal (step  58 ). 
         [0054]    Then, the system detects whether the HS/VS/DE (horizontal sync, vertical sync and data enable) of the R/G/B channels are normal  59 . When the signals are abnormal, the system maintains operating in the power-saving mode. When the signals are normal, the system enters the operation in the normal mode (step  50 ). 
         [0055]    To sum up, the present invention provides an apparatus and method for power-saving and wake-up. The signal receiving device system is working in the operation of normal mode. The system will turn off partial circuits&#39; power and enter the operation in power-saving mode when the cable signal, the clock signal and data signal are abnormal. Thus, the present invention not only realizes the effect of power saving and reduce power but also monitors the receiver at any time. When the detected signal is normal, the system executes a wake up procedures and effectively turns on the receiver power to enter the normal mode. 
         [0056]    While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.