Abstract:
An information processing apparatus comprising a first communication device configured to receive an external signal, a second communication device configured to receive an external signal different from the external signal received by the first communication device, power supply part which selectively supplies power to one of the first communication device and the second communication device in a power-supply-off state, and a part which activates the information processing apparatus based on the signal received by one of the first communication device and the second communication device to which power is supplied from the part which activates the information processing apparatus.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-190899, filed Jun. 28, 2002, the entire contents of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to an information processing apparatus which is suitable to a PDA, a hand-held type personal computer and the like, and a power supply control method.  
           [0004]    2. Description of the Related Art  
           [0005]    In recent years, easily portable information processing apparatuses such as PDA (personal digital assistant) and hand-held type personal computer have become increasingly popular.  
           [0006]    Many such information processing apparatuses which incorporate wireless communication means become widely available due to the development of wireless communication technologies. In addition, apparatuses which can be conveniently connected to communication networks become also widely available.  
           [0007]    The wireless communication means includes wireless communication methods based on Bluetooth™ and the IEEE 802.11 Standard, and wireless communication is realized by incorporating the wireless communication means in the information processing apparatus.  
           [0008]    Card devices having wireless communication functions have also been developed in recent years. Therefore, even in a case that the information processing apparatus does not incorporate such wireless communication means, wireless communication can be performed easily by inserting the wireless card device is into a predetermined card slot provided to the information processing apparatus.  
           [0009]    Some information processing apparatus having wireless communication functions are also provided with a wakeup technique. In other words, they are adapted to receive an external signal by way of wireless communication means when the power supply of the information processing apparatus is turned off and the received signal is used as trigger for activating the information processing apparatus.  
           [0010]    To realize the wakeup technique, the power supply to the wireless communication card inserted into the card slot must be kept even when the power supply is turned off. Therefore, the power of the power supply is wasted in the mobile information processing device using a battery whose capacity is limited.  
           [0011]    Some information processing apparatuses are adapted to address this problem by allowing the user to select either use or non-use of the wakeup technique. If use of the wakeup technique is selected, the apparatus is ready for wakeup operations although power may be consumed to some extent. If, on the other hand, non-use of the wakeup technique is selected, power will not be consumed at all so long as the power supply of the apparatus is off.  
           [0012]    However, with such an arrangement, the user is forced to select only either use or non-use of the wakeup technique if his or her information processing apparatus is provided with a plurality of communication devices including wireless communication cards that are adapted to wakeup operations. In other words, known information processing apparatus of the type under consideration are not designed to elaborately define the tradeoff of power consumption and wakeup operations.  
         BRIEF SUMMARY OF THE INVENTION  
         [0013]    An information processing apparatus according to a first aspect of the invention comprises: a first communication device configured to receive an external signal; a second communication device configured to receive an external signal different from the external signal received by the first communication device; means for selectively supplying power to one of the first communication device and the second communication device in a power-supply-off state; and means for activating the information processing apparatus based on the signal received by one of the first communication device and the second communication device to which power is supplied from the means for activating the information processing apparatus.  
           [0014]    A power supply control method of an information processing apparatus, which comprises a first communication device configured to receive an external signal and a second communication device configured to receive an external signal different from the external signal received by the first communication device, according to a second aspect of the invention comprises: selectively supplying power to one of the first communication device and the second communication device in a power-supply-off state of the information processing apparatus; and activating the information processing apparatus based on the signal received by way of one of the first communication device and the second communication device to which power is selectively supplied.  
           [0015]    A power supply control method according to a third aspect of the invention of an information processing apparatus, which comprises a first communication device configured to receive an external signal and a second communication device configured to receive an external signal different from the external signal received by the first communication device, at least one of the communication devices being removably fitted to the information processing apparatus, comprises: selectively supplying power to one of the first communication device and the second communication device in a power-supply-off state of the information processing apparatus; activating the information processing apparatus based on the signal received by way of one of the first communication device and the second communication device to which power is selectively supplied; stopping the power supply to one of the first communication device and the second communication device to which power is supplied at detection of the removal thereof from the information processing apparatus; starting supplying power to one of the second communication device and the first communication device to which power has not been supplied in place of the communication device whose power supply ahs been stopped; and restarting supplying power to the fitted communication device and stopping the power supply to the communication device to which power has been supplied, when the removed device is refitted to the information processing apparatus. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0016]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serves to explain the principles of the invention.  
         [0017]    [0017]FIG. 1 shows the external configuration of a personal computer according to an embodiment of the present invention;  
         [0018]    [0018]FIG. 2 is a block diagram showing a part of the circuit in the personal computer according to the embodiment;  
         [0019]    [0019]FIG. 3 is a flow chart showing the processing operation according to the embodiment when the wakeup technique is selected;  
         [0020]    [0020]FIG. 4 is a flow chart showing the processing operation at the wakeup operation according to the embodiment; and  
         [0021]    [0021]FIG. 5 is a block diagram showing a part of another circuit in the personal computer according to the embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    Now, the embodiment of the present invention will be described with reference to the accompanying drawings in a case that the embodiment of the present invention is applied to the notebook-type personal computer.  
         [0023]    [0023]FIG. 1 is a schematic perspective view of the personal computer (PC)  10 . As shown in FIG. 1, a display section  13  that also operates as cover is linked to main body case  11  by means of hinge mechanisms  12 ,  12  so as to make the personal computer  10  foldable.  
         [0024]    The display section  13  includes a color liquid crystal panel  14  having a backlight and a power switch  15  at the inner surface side thereof.  
         [0025]    The main body case  11  has a keyboard  16 , which includes a pointing device, arranged on the top side thereof, a PC card slot  17 , which is based on the PCMCIA Standard, arranged at the right side thereof and an SD (secure digital) card slot  18  arranged at the left end of the front side thereof.  
         [0026]    A wireless LAN card  19  based on the IEEE 802.11 Standard is removably fitted to the PC card slot  17  as a communication device for receiving a wakeup signal.  
         [0027]    On the other hand, a Bluetooth card  20  adapted to transmit data to and receive data from an external device according to the Bluetooth Standard is removably fitted to the SD card slot  18  as a communication device for receiving a wakeup signal.  
         [0028]    [0028]FIG. 2 shows a part of the circuit in the personal computer  10 .  
         [0029]    Referring to FIG. 2, a CPU and north bridge circuit  21  processes various data when the power supply of the personal computer  10  is on.  
         [0030]    A south bridge circuit  23  and card controller  24  are connected to the CPU+north bridge circuit  21  by way of a PCI (peripheral component interconnect) bus  22 .  
         [0031]    The south bridge circuit  23  is a controller which performs data conversion, traffic control and other operations between the PCI bus  22  and ISA bus  26 .  
         [0032]    The south bridge circuit  23  is connected to RTC (real time clock)  25 . Additionally, the south bridge circuit  23  is connected to a BIOS-ROM  27  by way of the ISA (industry standard architecture) bus  26 , to an EC (embedded controller)  29  by way of a serial bus  28  and an HDD (hard disk drive)  31  by way of an IDE interface (I/F)  30 .  
         [0033]    The RTC  25  keeps time of the current clock time regardless of the power supply is in an on or off state.  
         [0034]    The BIOS-ROM  27  is a ROM securely storing the BIOS (basic input/output system).  
         [0035]    The HDD  31  stores an OS (operating system), various application programs and data files, etc.  
         [0036]    The card controller  24  controls the operation of exchanging data between the cards fitted respectively to the PC card slot  17  and the SD card slot  18  and the CPU+north bridge circuit  21  and the south bridge circuit  23  by way of the PCI bus  22 . The card controller  24  includes a PC card controller  24   a  and an SD card controller  24   b .  
         [0037]    A signal line connecting the card controller  24  and the PC card slot  17  is also connected to the EC  29 . When the wireless LAN card  19  is fitted to or removed from the PC card slot  17 , the card detection signal CD-P output from the card controller  24  and the wakeup signal detected by the wireless LAN card  19  are transmitted to the EC  29 .  
         [0038]    Similarly, the signal line connecting the card controller  24  and the SD card slot  18  is also connected to the EC  29 . As the Bluetooth card  20  is fitted to or removed from the SD card slot  18 , the card detection signal CD-S output from the card controller  24  and the wakeup signal detected by the Bluetooth card  20  are transmitted to the EC  29 .  
         [0039]    The EC  29  receives wakeup signals from the card controller  24  and is connected to card power supply controller  32 , power supply switch  15 , battery  33  and power supply controller  34 .  
         [0040]    The card power supply controller  32  supplies driving power supply PC-V for driving the wireless LAN card  19  to the PC card slot  17  and to the PC card controller  24   a  of the card controller  24  in response to the signal given from the EC  29  and the control signal from the card controller  24 . On the other hand, the card power supply controller  32  supplies driving power supply SD-V for driving the Bluetooth card  20  to the SD card slot  18  and the SD card controller  24   b  of the card controller  24 .  
         [0041]    The battery  33  is one of the power supplies of the personal computer  10 . Typically, a rechargeable type battery such as lithium ion type battery is used. The battery  33  supplies the power to a DC-DC converter  35  by way of a diode D 1  and also to the power supply controller  34 .  
         [0042]    When an AC plug  36  for AC driving the personal computer  10  is connected to an AC plug socket (not shown), AC power supplied through the AC plug  36  is rectified and stepped down by the AC adapter  37  and is supplied to the DC-DC converter  35  by way of the diode D 2 .  
         [0043]    The DC-DC converter  35  converts the supplied power into several predetermined voltages and supplies them respectively to a number of circuits including the card power supply controller  32  under the control of the power supply controller  34 .  
         [0044]    The diodes D 1 , D 2  are provided in order to prevent the electric currents from the battery  33  and the AC adapter  37  from running into the other circuits.  
         [0045]    The power supply controller  34  monitors the voltage condition of the battery  33  and controls the operation of the DC-DC converter  35 . At the same time, the power supply controller  34  reports the voltage condition of the battery  33  to the EC  29 .  
         [0046]    Operation of the above-described embodiment will be explained.  
         [0047]    Assume that the wireless LAN card  19  and the Bluetooth card  20  are fitted respectively into the PC card slot  17  and the SD card slot  18  in advance in the embodiment.  
         [0048]    As the wireless LAN card  19  and the Bluetooth card  20  are fitted into the respective slots, the EC  29  reads and holds the identification information specific to each of the cards, for example, tuple information by way of the card controller  24 .  
         [0049]    [0049]FIG. 3 shows the processing operation, from the time when the power supply is turned on by operating the power supply switch  15  to the time when the wireless LAN card  19  and the Bluetooth card  20  are selected as communication devices adapted to receive a wakeup signal if the power supply is turned off.  
         [0050]    In this embodiment, the EC  29  mainly performs the processing operation.  
         [0051]    Firstly, when the power supply is in an off state, the EC  29  judges repeatedly if the power supply switch  15  is operated or not and waits for the time when the power supply switch  15  is operated (Step A 01 ).  
         [0052]    As the power supply switch  15  is operated, the EC  29  detects the operation thereof and starts to activate the OS stored in the HDD  31  by the south bridge circuit  23  (Step A 02 ).  
         [0053]    In the process of starting to activate the OS, the EC  29  temporarily supplies the PC card controller  24   a  of the card controller  24  and the wireless LAN card  19  with power supply PC-V and, at the same time, the SD card controller  24   b  of the card controller  24  and the Bluetooth card  20  with power supply SD-V by means of the card power supply controller  32 .  
         [0054]    During the various preparatory operations of the OS, it is determined if the wireless LAN card  19  and/or the Bluetooth card  20  are selected as communication devices for receiving a wakeup signal or not (Step A 03 ). If neither of them is selected, the EC  29  enters some other processing operation.  
         [0055]    If, on the other hand, the wireless LAN card  19  and/or the Bluetooth card  20  are selected as communication devices for receiving a wakeup signal in Step A 03 , the wireless LAN card  19  and/or the Bluetooth card  20  are defined to operate as wakeup devices based on various utility settings (Step A 04 ). Subsequently, it is determined if wakeup is defined for the wireless LAN card  19  and/or the Bluetooth card  20  or not (Step A 05 ). When the wakeup is defined, it is determined if at least one of the wireless LAN card  19  fitted to the PC card slot  17  and the Bluetooth card  20  fitted to the SD card slot  18  is selected to operate as wakeup device or not.  
         [0056]    If it is determined that at least one of them is selected, it is determined if only the Bluetooth card  20  fitted to the SD card slot  18  is selected as communication device for receiving a wakeup signal or not (Step A 06 ).  
         [0057]    If it is determined that only the Bluetooth card  20  is selected as communication device for receiving a wakeup signal, power is supplied only to the circuits associated with the Bluetooth card  20 . More specifically, only the power supply SD-V is activated and power supply SD-V is supplied only to the SD card controller  24   b  of the card controller  24  and the Bluetooth card  20  by means of the card power supply controller  32 . On the other hand, the power supply PC-V is deactivated so that no power supply PC-V is supplied to the PC card controller  24   a  of the card controller  24  and the wireless LAN card  19  (Step A 07 ).  
         [0058]    If, on the other hand, it is determined in Step A 06  that it is not only the Bluetooth card  20  which is selected to operate as communication device for receiving a wakeup signal, it is determined if only the wireless LAN card  19  fitted to the PC card slot  17  is selected as communication device for receiving a wakeup signal or not (Step A 08 ).  
         [0059]    If it is determined that only the wireless LAN card  19  is selected as communication device for receiving a wakeup signal, power is supplied only to the circuits associated with the wireless LAN card  19 . More specifically, only the power supply PC-V is activated and power supply PC-V is supplied only to the PC card controller  24   a  of the card controller  24  and the wireless LAN card  19  by means of the card power supply controller  32 . On the other hand, the power supply SD-V is deactivated so that no power supply SD-V is supplied to the SD card controller  24   b  of the card controller  24  and the Bluetooth card  20  (Step A 09 ).  
         [0060]    Furthermore, if it is determined in Step A 08  that it is not only the wireless LAN card  19  which is selected to operate as communication device for receiving a wakeup signal, both of the wireless LAN card  19  and the Bluetooth card  20  are selected to operate as communication devices for receiving a wakeup signal. Therefore, power is supplied to the circuits associated with the wireless LAN card  19  and also to the circuits associated with the Bluetooth card  20 . More specifically, the power supply PC-V is activated and power supply PC-V is supplied to the PC card controller  24   a  of the card controller  24  and the wireless LAN card  19  by means of the card power supply controller  32 . At the same time, the power supply SD-V is activated and power supply SD-V is supplied only to the SD card controller  24   b  of the card controller  24  and the Bluetooth card  20  also by means of the card power supply controller  32  (Step A 10 ).  
         [0061]    If it is determined in Step A 04  that the wireless LAN card  19  and/or the Bluetooth card  20  are selected as communication devices for receiving a wakeup signal but it is determined in Step A 05  that neither of them is selected as wakeup device for receiving a wakeup signal, none of the processing operations of the above Steps A 07 , A 09  and A 10  will be executed.  
         [0062]    The power supply is turned off and held to a suspended state (Step A 11 ) when it is determined in Step A 05  that neither of the cards is selected to operate as communication device for receiving a wakeup signal or after the processing operations of Steps A 07 , A 09  and A 10 . The processing operation based on the selection of communication devices for receiving a wakeup signal is once ended through the above described steps, the operation enters the standby state of the wakeup signal.  
         [0063]    As pointed out above, if it is determined in Step A 05  that neither of the cards is selected to operate as communication device for receiving a wakeup signal, none of the processing operations of the above Steps A 07 , A 09  and A 10  will be executed. Therefore, when the power supply is held to a suspended state, both the power supply PC-V to the PC card controller  24   a  of the card controller  24  and the wireless LAN card  19  and the power supply SD-V to the SD card controller  24   b  of the card controller  24  and the Bluetooth card  20  by the card power supply controller  32  are stopped.  
         [0064]    The processing operation that is mainly performed by the EC  29  for waiting for a wakeup operation in a suspended state will be described with reference to FIG. 4.  
         [0065]    In a suspended state, it is determined if a wakeup signal is input from the wireless LAN card  19  or the Bluetooth card  20  or not (Step B 01 ).  
         [0066]    If no wakeup signal is input, it is determined if a card detection signal CD-P or CD-S, which indicates that the wireless LAN card  19  is fitted into the PC card slot  17  or the Bluetooth card  20  is fitted into the SD card slot  18 , is output from the card controller  24  or not (Step B 02 ).  
         [0067]    If no such card detection signal is detected, it is determined if there is a card detection signal CD-P or CD-S output from the card controller  24  as a result of an action that a new wireless LAN card  19  is fitted into the PC card slot  17  or a new Bluetooth card  20  is fitted into the SD card slot  18  or not (Step B 03 ).  
         [0068]    Thus, reception of a wakeup signal and fitting or removing a wireless LAN card  19  or a Bluetooth card  20  are monitored by repeatedly executing the determining steps B 01  through B 03 .  
         [0069]    If it is determined in Step B 01  that the wakeup signal is input from the wireless LAN card  19  or the Bluetooth card  20 , the EC  29  determines if the selection of the wireless LAN card  19  is changed to the Bluetooth card  20  or vice versa or not based on the input wakeup signal (Step B 04 ).  
         [0070]    Only if it is determined that such a change is set, the power supply SD-V to the SD card controller  24   b  and the Bluetooth card  20  is turned on in place of the power supply PC-V from the card power supply controller  32  provided that the wakeup signal is from the wireless LAN card  19 .  
         [0071]    Contrary, when the wakeup signal is from the Bluetooth card  20 , the power supply PC-V to the PC card controller  24   a  and the wireless LAN card  19  is turned on in place of the power supply SD-V from the card power supply controller  32 .  
         [0072]    Thereafter, the power-supply-on state is restored from the suspended state by the resume function (Step B 06 ) and, at this time, an operation of data communication with a nearby external communication device is started by the communication device to which power is supplied and which is adapted to receive a wakeup signal.  
         [0073]    The processing operation in Step B 04  or B 05  is for controlling the suitable data communication system in a standby state waiting for a wakeup signal or in data communication state under a mobile computing environment, whichever appropriate.  
         [0074]    More specifically, in a suspended state, the Bluetooth card  20  that consumes standby power only at a low rate is made to perform a standby operation waiting for a wakeup signal. If the personal computer  10  is moved to a location where it can conducts wireless communication with an external device, the wireless LAN card  19  is selected and used for wireless communication because it is far advantageous in terms of data transfer rate, although it consumes standby power at a rate that is incomparably higher than the power consumption rate of the Bluetooth card  20 .  
         [0075]    If it is determined in Step B 02  that a card detection signal CD-P or CD-S is output from the card controller  24 , it is then determined that the detection signal is CD-S or not (Step B 07 ).  
         [0076]    If it is determined that the detection signal is CD-S, it means that the Bluetooth card  20  is removed. Therefore, the identification information of the Bluetooth card  20  which has been fitted is held and the power supply SD-V from the card power supply controller  32  to the SD card controller  24   b  and the Bluetooth card  20  is turned off to stop the power supply (Step B 08 ). Then, the standby state from Step B 01  is resumed.  
         [0077]    At this time, as shown in ( ) of FIG. 4, it may be arranged that the power supply PC-V from the card power supply controller  32  to the PC card controller  24   a  and the wireless LAN card  19  is newly turned on to start the power supply so as to enter a standby state of waiting for a wakeup operation by a different wireless communication system.  
         [0078]    If it is determined in Step B 07  that the card detection signal output from the card controller  24  is not CD-S, it means that the detection signal is CD-P and the wireless LAN card  19  is removed from the PC card slot  17 . Therefore, the EC  29  holds the identification information of the wireless LAN card  19  which has been fitted to the card slot.  
         [0079]    Thereafter, the EC  29  turns off the power supply PC-V from the card power supply controller  32  to the PC card controller  24   a  and the wireless LAN card  19  to stop the power supply (Step B 09 ) and then the standby state from Step B 01  is resumed.  
         [0080]    At this time, as shown in ( ) of FIG. 4, it may be arranged that the power supply SD-V from the card power supply controller  32  to the SD card controller  24   b  and the Bluetooth card  20  is newly turned on to start the power supply so as to enter a standby state of waiting for a wakeup operation by a different wireless communication system.  
         [0081]    If it is determined in Step B 03  that there is a card detection signal CD-P or CD-S because a wireless LAN card  19  is newly fitted into the PC card slot  17  or a Bluetooth card  20  is newly fitted into the SD card slot  18 , it is then determined if the card that has been removed is newly fitted into the slot or not by determining if the identification information of the newly fitted card  19  or  20  agrees with the identification information of the card which was fitted in the card slot  17  or  18  (Step B 10 ).  
         [0082]    Only if the two pieces of identification information agree with each other, power supply PC-V or SD-V is supplied from the card power supply controller  32  to the PC card controller  24   a  and the wireless LAN card  19  or to the SD card controller  24   b  and the Bluetooth card  20 , because the card that has been removed is fitted into the corresponding slot once again (Step B 11 ). Thereafter, the standby state from Step B 01  is resumed.  
         [0083]    Thus, when a plurality of communication devices such as a wireless LAN card  19  and a Bluetooth card  20  are provided, power is supplied in a power off state, or a suspended state, only to the card which is selected for a wakeup operation. With this arrangement, it is possible to wait for a wakeup operation, while minimizing the power consumption.  
         [0084]    Additionally, since the wireless LAN card  19  and the Bluetooth card  20  can be respectively removably fitted into the PC card slot  17  and the SD card slot  18 , it is possible to remove the wireless LAN card  19  and the Bluetooth card  20  while waiting for a wakeup operation.  
         [0085]    Therefore, if the communication device in question, which is the wireless LAN card  19  or the Bluetooth card  20 , is removed, the removal is detected immediately and the power supply to the card is stopped immediately. Waste of power is effectively avoided with this arrangement.  
         [0086]    As described above for Step B 08  or B 09 , the standby state waiting for a wakeup operation can be maintained by supplying power to the other communication device that remains in the corresponding slot.  
         [0087]    If the communication devices of the wireless LAN card  19  or the Bluetooth card  20  is removed and a card is newly fitted into the slot, it is possible to recognize if a right communication device is fitted into the slot or not by determining if the identification information of the removed card and that of the newly fitted communication device agree with each other or not because the identification information of the wireless LAN card  19  and that of the Bluetooth card  20  are held.  
         [0088]    Thus, if the communication device that has been removed from the corresponding slot is refitted into the slot, the sameness is recognized and power is supplied to the device so that the standby state waiting for a wakeup operation is resumed.  
         [0089]    If the power supply system for continuing the standby state waiting for a wakeup operation is switched to another system as indicated in Step B 08  or B 09 , the power supply by the another power supply system is stopped and the power supply by the original power supply system is resumed to continue the standby state waiting for a wakeup operation in order to avoid waste of power when the communication device is fitted back into the slot.  
         [0090]    The RTC  25  which times the current clock time is connected to the south bridge circuit  23  regardless if the power supply is on or off. Therefore, if the time zone in which a wakeup operation will take place is defined and information on the defined time zone is stored in the EC  29  in advance, it is possible to supply power from the card power supply controller  32  to the wireless LAN card  19  and the associated devices or to the Bluetooth card  20  and the associated devices only during the defined time zone under the control of the EC  29  with reference to the current time shown by the RTC  25  which is connected to the south bridge circuit  23 .  
         [0091]    With this arrangement, the power supply to the communication devices is stopped during the time zone in which it is not necessary to keep the standby state waiting for a wakeup signal so that waste of power can be avoided reliably in that time zone.  
         [0092]    In the above described embodiment, the power supply is turned off to automatically get into a suspended state of maintaining the operating conditions of the operating system and the application programs after setting a wakeup operation as shown in FIG. 3.  
         [0093]    As the power supply is turned off in the suspended state, the operating system and the application programs are started quickly to activate any selected application program when the power supply is turned on subsequently by a wakeup operation if compared with an arrangement of completely ending the operations of the operating system and the application programs and the power supply is terminated.  
         [0094]    (Modification to the Embodiment)  
         [0095]    [0095]FIG. 5 shows a part of the circuit of another personal computer  10  which differs from that of FIG. 2.  
         [0096]    The personal computer  10  shown in FIG. 5 is basically the same as that of FIG. 2. Therefore, the components that are the same as those of FIG. 2 are denoted respectively by the same reference symbols and will not be described any further.  
         [0097]    In FIG. 5, an interface connecting/disconnecting Q (quick) switch  41  (denoted by “Q-SW” in FIG. 5) is arranged between the card controller  24  and the PC card slot  17  for switching from allowing data to pass through to blocking data from passing through and vice versa.  
         [0098]    Similarly, an interface connecting/disconnecting Q-switch  42  is arranged between the card controller  24  and the SD card slot  18  for switching from allowing data to pass through to blocking data from passing through and vice versa.  
         [0099]    Each of the Q-switches  41 ,  42  is switched to block data from passing through unless the wireless LAN card  19  or the Bluetooth card  20  is used for a standby state waiting for a wakeup operation.  
         [0100]    With this arrangement, it is possible to reliably avoid power being supplied from the card controller  24  to either the wireless LAN card  19  or the Bluetooth card  20  from being supplied to the other communication device so that waste of power is securely eliminated.  
         [0101]    The above embodiment is exemplified to a personal computer  10  in which a wireless LAN card  19  is fitted into the PC card slot  17  and a Bluetooth card  20  is fitted into the SD card slot  18 , but the present invention is not limited to the above embodiment. The present invention is applicable to any portable registered terminal of a PDA or POS (point of sales) system in which the portable information apparatus comprises a plurality of devices capable of a wakeup operation such as wired LAN interface.  
         [0102]    In the above embodiment, communication devices which are removably fitted to corresponding respective slots are described, but the present invention is not limited to the above described embodiment. In other words, the present invention is applicable to a plurality of any internal communication devices.  
         [0103]    Additionally, the present invention is not limited to the above described embodiment, which may be modified or altered in various different ways within the scope of the invention.  
         [0104]    Furthermore, the above described embodiment contains various stages of invention so that various inventions may be drawn by appropriately combining a plurality of disclosed components. For example, if at least one of the objects of the present invention as pointed out earlier is achieved and at least one of the advantages as pointed out above is obtained even when a number of components are deleted from the entire components of the embodiment, the arrangement obtained by deleting those components can be drawn as invention.  
         [0105]    Thus, the above described embodiment of the invention comprises a plurality of communication devices adapted to receive a wakeup signal and can be held in a standby state for receiving a wakeup signal, while avoiding waste of power, because power is supplied only to one of the communication devices selected to operate for receiving a wakeup signal when the power supply of the main body is turned off.  
         [0106]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the present invention in its broader aspects is not limited to the specific details, representative devices and illustrated examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.