JP4687135B2 - Mobile communication terminal and clock control method thereof - Google Patents

Description

  The present invention relates to a mobile communication terminal and a clock control method thereof, and more particularly to a mobile communication terminal such as a mobile phone that performs an intermittent reception operation using a timer and a clock control method thereof.

  FIG. 2 is a block diagram showing an example of a main part of a conventional mobile communication terminal. In the figure, a chip set 200 of a cellular phone is an electric circuit unit combined with a large-scale semiconductor integrated circuit (LSI), excluding a transmitter / receiver unit, an input unit, a display unit, and the like. It comprises a clock generator 103, a memory 104, a low-speed clock generator 105, a modem unit 201, and a central processing unit (CPU) 210.

  The transmitter / receiver unit 101 is a circuit unit that transmits and receives radio signals to and from the nearest base station (not shown) based on the radio synchronization clock from the radio synchronization clock generator 103. The modulation / demodulation unit 201 uses the clock obtained by multiplying the radio synchronization clock from the radio synchronization clock generator 103 to a predetermined frequency by the radio synchronization multiplication circuit 202, and the analog signal I received by the transmission / reception unit 101. The signal and the Q signal are demodulated into data and supplied to the CPU 210, and the data input from the CPU 210 is modulated and converted into an analog I signal and Q signal and supplied to the transmitting / receiving unit 101.

  The CPU 210 includes a processor 211 that operates according to a program stored in the memory 104, a high-speed peripheral circuit 212 that requires a high-speed clock, a low-speed peripheral circuit 213 that requires a low-speed clock and includes a timer 214, and a low-speed A frequency multiplier 215 that multiplies the low-speed clock from the clock generator 105 and outputs it to the processor 211 and the high-speed peripheral circuit 212 is included. In this conventional mobile communication terminal, intermittent operation is performed based on a signal from the timer 214.

  In addition, since a communication signal is intermittently received, a portable communication terminal that is activated by a timer activation signal, activates a synthesizer, determines a frequency and phase, establishes synchronization, and starts data reception from the past. It is known (see, for example, Patent Document 1). The conventional portable communication terminal described in Patent Document 1 aims to reduce power consumption by minimizing transmission to a base station and minimizing intermittent reception.

  Furthermore, when it is time to start a cell search for searching for a synchronization radio channel of the base station, the timer instructs the radio unit to start activation, and instructs the start of clock operation. A portable communication terminal that performs start and stop control using a timer is also known (see, for example, Patent Document 2).

JP 2002-344375 A (page 4-5) Japanese Patent Laying-Open No. 2004-221671 (page 8, FIG. 1)

  However, in the conventional mobile communication terminal shown in FIG. 2, the clock system used for wireless synchronization and the clock system used by the CPU 210 are different, and therefore the multiplier circuit 215 must always operate during intermittent reception. In order to save power, the multiplier circuit 215 cannot be stopped, and there is a problem that power is consumed wastefully.

  Also, the conventional mobile communication terminal described in Patent Document 1 realizes intermittent reception by synchronizing the timing of transmission and reception between the terminal and the base station, and stops generating unnecessary clocks inside the terminal. Doing so does not reduce power consumption. Furthermore, the conventional mobile communication terminal described in Patent Document 2 is stationary when the level indicating the channel quality of the base station on standby is equal to or higher than a predetermined threshold, and the surrounding channel status is Power consumption is determined by stopping the operation of the radio unit and clock control unit until the timing of the next newly detected cell search by setting the execution cycle of the newly detected cell search by the timer to be long by judging that it is in a good state However, when the level indicating the channel quality of the base station in standby is less than a predetermined threshold, the power consumption cannot be reduced.

  The present invention has been made in view of the above points, and provides a portable communication terminal capable of reducing power consumption by stopping generation of an unnecessary clock inside the terminal during intermittent reception regardless of cell search, and a clock control method thereof. The purpose is to do.

In order to achieve the above object, the present invention provides a mobile communication terminal that performs intermittent reception at a set time of a timer, and synchronizes a low-speed clock generating means that generates a low-speed clock with a radio synchronization clock between the base station and the base station. Transmitting / receiving means for modulating / demodulating a transmission signal and a reception signal based on a first clock, an arithmetic processing means operating in synchronism with the second clock, and controlling each part of the terminal in an integrated manner, A second clock and a third clock to be used inside the terminal by multiplying the clock, and a frequency multiplier that supplies or shuts off power by a control signal from the timer, and the timer has a reception period for intermittent reception. The power supply to the multiplication unit is stopped during the period, and the power supply to the multiplication unit is controlled during the non-reception period of intermittent reception. In the present invention, the power consumption of the multiplication means can be reduced to zero by stopping the supply of power to the multiplication means during the reception period of intermittent reception.

  In order to achieve the above object, the present invention provides a wireless synchronization clock generating means for generating a wireless synchronization clock and a low speed clock for generating a low speed clock in a portable communication terminal that performs intermittent reception at a set time of a timer. Radio communication between the generating means and the base station in synchronism with the clock for radio synchronization, transmission / reception means for modulating / demodulating the transmission signal and the reception signal based on the first clock, and synchronizing with the second clock An arithmetic processing unit that operates and controls each part of the terminal in an integrated manner, a first multiplying unit that generates a first clock and a second clock by multiplying a radio synchronization clock, and a low-speed clock that is multiplied A second multiplying unit that generates a second clock and a third clock used inside the terminal, and that is supplied or cut off by a control signal from the timer; and a control from the timer The first clock obtained by the first multiplying means is supplied to the transmitting / receiving means during the reception period of the intermittent reception based on the signal, and the second clock obtained by the first multiplying means is used as the arithmetic processing means. And a clock control means for supplying the second clock obtained by the second multiplying means to the arithmetic processing means during the non-reception period of intermittent reception, and the timer is second during the reception period of intermittent reception. The power supply to the frequency multiplication means is stopped, and control is performed so that the power supply to the second frequency multiplication means is supplied during the non-reception period of intermittent reception.

  In the present invention, during the reception period of intermittent reception, the first and second clocks obtained by multiplying the clock for radio synchronization can be used for the transmission / reception means and the arithmetic processing means, respectively, and the reception period of intermittent reception is also possible. In the middle, the power consumption of the multiplication means can be made zero by stopping the supply of power to the multiplication means. Here, the timer operates in synchronization with a low-speed clock.

In order to achieve the above-mentioned object, the present invention comprises a transmitting / receiving means for performing wireless communication with a base station in synchronization with a wireless synchronization clock, and modulating / demodulating a transmission signal and a reception signal based on a first clock; A clock control method for a mobile communication terminal, comprising: arithmetic processing means that operates in synchronization with the second clock and that controls each part of the terminal in an integrated manner, and that performs intermittent reception at a set time of a timer under control of the arithmetic processing means A first step of generating a first clock and a second clock by multiplying a clock for radio synchronization, and a first step during a reception period of intermittent reception based on a control signal from a timer. Based on the control signal from the timer, the second step of supplying the second clock obtained in the first step to the arithmetic processing means, A third step of generating a second clock obtained by multiplying the low-speed clock supplied to the timer and a third clock used inside the terminal during the non-reception period of the missing reception and supplying the third clock to the arithmetic processing means; And the timer is controlled to pause the low-speed clock multiplication operation in the third step during the intermittent reception period.

  In the present invention, during the reception period of intermittent reception, the first and second clocks obtained by multiplying the clock for radio synchronization can be used for the transmission / reception means and the arithmetic processing means, respectively, and the reception period of intermittent reception is also possible. In the middle, the power consumption of the multiplication means can be made zero by stopping the supply of power to the multiplication means.

  According to the present invention, the first and second clocks obtained by multiplying the clock for radio synchronization are used for the transmission / reception means and the arithmetic processing means, respectively, during the reception period of intermittent reception synchronized with the set time by the timer. Because the clock for radio synchronization can be used in common, power saving can be realized, and furthermore, the power consumption of the multiplier is made zero by stopping the supply of power to the multiplier Thus, power consumption during the reception period can be significantly reduced as compared with the conventional case.

  Next, the best mode for carrying out the invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a main part of a portable communication terminal according to the present invention. In the figure, the same components as those in FIG. In FIG. 1, a chip set 100 of a mobile phone which is an embodiment of a mobile communication terminal includes an electric circuit unit combined with a large-scale semiconductor integrated circuit (LSI), excluding a transmitter / receiver unit, an input unit, a display unit, and the like. The transmission / reception unit 101, the modulation / demodulation unit 102, the wireless synchronization clock generator 103, the memory 104, the low-speed clock generator 105, and the central processing unit (CPU) 110.

  The transmitter / receiver unit 101 is a circuit unit that transmits / receives a radio signal to / from the nearest base station (not shown) based on the radio synchronization clock from the radio synchronization clock generator 103, and is received from the base station. The radio signal is subjected to reception processing to obtain an analog I signal and Q signal and output to the modem unit 102. The I signal and Q signal for transmission from the modem unit 102 are in a predetermined radio frequency band (RF signal band). The frequency is converted to and transmitted to the base station.

  Unlike the conventional modulation / demodulation unit 201, the modulation / demodulation unit 102 uses a clock obtained by multiplying the radio synchronization clock from the radio synchronization clock generator 103 to a predetermined frequency by the radio synchronization multiplication circuit 116 in the CPU 110. The analog signal I and Q signals obtained by receiving at 101 are demodulated into data and supplied to the CPU 110, and the data for transmission input from the CPU 110 is modulated and converted into analog signals I and Q signals. To the transceiver 101.

  The CPU 110 is a high-speed peripheral circuit that is a set of peripheral circuits that require a high-speed clock and a processor 111 for comprehensively controlling the operation of the entire mobile phone according to this embodiment in accordance with a program stored in the memory 104 112, a low-speed peripheral circuit 113 that is a set of peripheral circuits that require a low-speed clock such as a timer 114, a multiplier circuit 115 that multiplies the low-speed clock from the low-speed clock generator 105, and a radio synchronization multiplier. A clock control circuit 117 for selecting one of the clock for wireless synchronization from the circuit 116 and the clock from the multiplication circuit 115 and supplying the clock to the processor 111 and the high-speed peripheral circuit 112 is included.

  The high-speed peripheral circuit 112 has a function of adjusting the data flow with the modem 102 and the data flow with the memory 104. When communication from the chipset 100 to the outside is performed, a circuit necessary for communication is included in either the high-speed peripheral circuit 112 or the low-speed peripheral circuit 113. The timer 114 is used during intermittent reception and serves as a trigger for starting the CPU 110 at a timing necessary for reception. The timer 114 controls the clock control circuit 117 and supplies a clock to the processor 111 and the high-speed peripheral circuit 112. At the same time, the timer 114 outputs a control signal for the multiplier circuit 115.

  The wireless synchronization multiplication circuit 116 multiplies the clock from the wireless synchronization clock generator 103 to a high-speed clock frequency (for example, 122 MHz) that can be used by the modem unit 102, the processor 111, and the high-speed peripheral circuit 112. The clock control circuit 117 controls whether to use the high-speed clock from the radio synchronization multiplier circuit 116 or the clock from the multiplier circuit 115. The multiplier circuit 115 multiplies the low-speed clock (for example, 32 kHz) from the low-speed clock generator 105 to the frequency of the high-speed clock that can be used by the processor 111 and the high-speed peripheral circuit 112.

  The memory 104 stores a program used by the processor 111 in advance, and data to be processed by the processor 111 is written and read out as necessary. The wireless synchronization clock generator 103 outputs a clock faster than the low-speed clock generator 105 as a reference clock for the transmission / reception unit 101. The low-speed clock generator 105 outputs a clock that is slower and consumes less power than the wireless synchronization clock generator 103.

  Next, the operation at the time of intermittent reception of the mobile phone according to the present embodiment will be described. In a portable telephone using a battery as an operating power source for portability, an intermittent reception operation has been conventionally performed from the viewpoint of saving power for the purpose of making the battery as long as possible. When the cellular phone according to the present embodiment performs the intermittent reception operation, the processor 111 sets a timer for a necessary time until the next reception start time in the timer 114 and shifts to the power saving state. In this power saving state, the clock control circuit 117 is controlled by the control signal from the timer 114, the clock from the multiplier circuit 115 is supplied to the processor 111 and the high-speed peripheral circuit 112, and the mobile phone is in a non-receiving operation state. .

  When the timer set time by the timer 114 expires, the mobile phone shifts from the previous non-reception operation state to the reception operation state. At this time, the timer 114 controls the clock control circuit 117 by the control signal, selects the clock output from the radio synchronization multiplier 116 and supplies it to the processor 111 and the high-speed peripheral circuit 112, and at the same time, the timer 114 controls the control signal. Thus, the power supply to the multiplier circuit 115 is stopped.

  As a result, during the reception operation period, the multiplier circuit 115 is deactivated to reduce its power consumption to zero, and the clock supplied from the wireless synchronization multiplier circuit 116 to the modem unit 102 is sent to the processor 111 and the high-speed peripheral circuit. By supplying to the circuit 112 at the same time, it is possible to realize power saving by sharing a clock. When the reception operation period continues for a predetermined time, the processor 111 sets the timer 114 again and shifts to the power saving state of the non-reception operation period.

  Next, operations other than the intermittent reception of the mobile phone according to the present embodiment will be described. In the case of processing that does not use the clock from the wireless synchronization clock generator 103, such as referring to data stored in the memory 104, the clock control circuit 117 supplies the clock from the multiplication circuit 115. The operation of this part is performed by the same processing as conventional interrupt processing.

  The present invention is not limited to the above embodiment. For example, the basic configuration of a mobile phone is as shown in FIG. 1, but unlike FIG. 1, the modem unit 102 and the CPU 110 are integrated. Also good. In the above embodiment, the power supply of the multiplier circuit 115 is controlled by the control signal from the timer 114. However, if there is an external power supply LSI, control to the power supply LSI is performed. It is possible to prepare a control signal for performing the same control. Furthermore, the present invention is not limited to a mobile phone, and can be widely applied to a simple mobile phone (PHS), a simple information device (PDA), and other mobile communication terminals.

It is a block diagram of the principal part of one embodiment of the present invention. It is a block diagram of the principal part of an example of the past.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Chipset 101 Transmission / reception part 102 Modulation / demodulation part 103 Wireless synchronous clock generator 104 Memory 105 Low speed clock generator 110 Central processing unit (CPU)
111 Processor 112 High-Speed Peripheral Circuit 113 Low-Speed Peripheral Circuit 114 Timer 115 Multiplier Circuit 116 Multiplier Circuit for Radio Synchronization 117 Clock Control Circuit

Claims (4)

In a mobile communication terminal that performs intermittent reception at the set time of the timer,
A low-speed clock generating means for generating a low-speed clock;
Radio transmission / reception means for performing radio communication with a base station in synchronization with a radio synchronization clock, and modulating / demodulating a transmission signal and a reception signal based on a first clock;
Arithmetic processing means that operates in synchronization with the second clock and controls each part of the terminal comprehensively;
A multiplier that multiplies the low-speed clock to generate the second clock and a third clock to be used in the terminal, and that supplies or shuts off power according to a control signal from the timer; A portable communication terminal, wherein control is performed so that power supply to the multiplication unit is stopped during a reception period of intermittent reception, and power supply to the multiplication unit is supplied during a non-reception period of intermittent reception. In a mobile communication terminal that performs intermittent reception at the set time of the timer,
A wireless synchronization clock generating means for generating a wireless synchronization clock;
A low-speed clock generating means for generating a low-speed clock;
Radio transmission / reception means for performing radio communication with a base station in synchronization with the clock for radio synchronization, and modulating / demodulating a transmission signal and a reception signal based on a first clock;
Arithmetic processing means that operates in synchronization with the second clock and controls each part of the terminal comprehensively;
First multiplication means for multiplying the wireless synchronization clock to generate the first clock and the second clock;
A second multiplying means for multiplying the low-speed clock to generate the second clock and a third clock used inside the terminal, and for supplying or shutting off power by a control signal from the timer;
Based on the control signal from the timer, the first clock obtained by the first multiplication means is supplied to the transmission / reception means during the reception period of intermittent reception, and obtained by the first multiplication means. Clock control means for supplying the second clock to the arithmetic processing means and supplying the second clock obtained by the second multiplying means to the arithmetic processing means during a non-reception period of intermittent reception. The timer is controlled to stop supplying power to the second multiplying means during the reception period of intermittent reception and to supply power to the second multiplying means during the non-reception period of intermittent reception. A mobile communication terminal. The timer, the mobile communication terminal according to claim 1 or 2, wherein the operating in synchronization with the low-speed clock. A terminal that performs radio communication with a base station in synchronization with a clock for radio synchronization, modulates and demodulates a transmission signal and a reception signal based on a first clock, and operates in synchronization with a second clock; A clock control method for a portable communication terminal, comprising: an arithmetic processing unit that comprehensively controls each unit, and performing intermittent reception at a set time of a timer under the control of the arithmetic processing unit,
A first step of multiplying the radio synchronization clock to generate the first clock and the second clock;
Based on the control signal from the timer, the first clock obtained in the first step is supplied to the transmission / reception means during the reception period of intermittent reception, and the first clock obtained in the first step is supplied. A second step of supplying two clocks to the arithmetic processing means;
Based on the control signal from the timer, the second clock obtained by multiplying the low-speed clock supplied to the timer during the non-reception period of intermittent reception and the third clock used inside the terminal are generated, and And a timer for controlling the multiplication of the low-speed clock by the third step during a reception period of intermittent reception. Terminal clock control method.

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