Abstract:
A portable computer includes a processor, a display device, an expansion slot with expansion card, and a communications module. The communications module having four modes that each restricts access in a different way to the expansion slot and corresponding expansion card resources by the processor and another computer. The mode of the communications module can be set by the communications module detecting states of a connection port and a wireless communications module of the portable computer. Alternatively, the mode of the communications module can be set by the processor and the other computer.

Description:
BACKGROUND OF INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a portable computer, and more specifically, to a portable computer having an expansion slot that can be directly accessed by another computer.  
           [0003]    2. Description of the Prior Art  
           [0004]    Being able to connect computers together to share resources is of benefit to computer users. As portable computers become increasingly popular, it is important for a user to be able to connect a portable computer with another computer to share information and resources.  
           [0005]    Many prior art portable computers have expansion slots for adding expansion cards to increase capabilities. For instance, referring to FIG. 1, a portable computer  10  has an expansion slot  12  that accepts a flash memory card  14 . When the flash memory card  14  is inserted into the expansion slot  12 , the portable computer  10  can access the flash memory card  14  and in effect, the portable computer  10  has more memory. Besides the flash memory card  14 , there are many other kinds of expansion cards that are readily available such as peripheral interface cards and network adaptors.  
           [0006]    The prior art portable computer  10  can also be connected to another computer, such as desktop computer (item  32  of FIG. 2), through a connection port  16  or a wireless communications module (item  18  of FIG. 2). When the portable computer  10  is connected to the desktop computer  32 , information can be exchanged between the portable computer  10  and the desktop computer  32 .  
           [0007]    Please refer to FIG. 2, which shows a block diagram of the prior art portable computer  10  connected to the desktop computer  32 . The portable computer  10  further comprises the wireless communications module  18  for connecting to the computer  32  wirelessly, an input/output (I/O) interface  20 , a processor  22 , a memory  24 , and a user interface  26 . The user interface  26  includes a display device  28 , such as a liquid crystal display (LCD), and an input device  30 . The I/O interface  20  allows commands and data to be exchanged between the processor  22  and the expansion slot  12 , the wireless communications module  18 , and the connection port  16 .  
           [0008]    If resources of the expansion slot  12 , and accordingly the flash memory card  14 , are to be shared with the computer  32 , the processor  22  must manage the exchange of information. Thus, the operating systems of the processor  22  and the computer  32  must be compatible. Additionally, the computer  32  is inherently limited in its access to the flash memory card  14  because of the processor managing the exchange of information.  
           [0009]    A major drawback of the prior art portable computer  10  is that the expansion slot  12  and accordingly the flash memory card  14  cannot be directly accessed by the desktop computer  32 . While the desktop computer  32  can indirectly access the information in the flash memory card  14  in a limited way through the processor  22 , the desktop computer  32  cannot utilize the flash memory card  14  as its own memory. This is also the case for other expansion cards that can be put into the expansion slot  12  of the portable computer  10 . Allowing direct access to the expansion card  14  by the desktop computer  32  is of importance in common situations such as when the portable computer  10  and desktop computer  32  have different operating systems.  
           [0010]    Therefore, the prior art lacks a portable computer having an expansion port that can be directly accessed by another computer.  
         SUMMARY OF INVENTION  
         [0011]    It is therefore a primary objective of the claimed invention to provide a portable computer that has an expansion slot that can be directly accessed by another computer to solve the problems of the prior art.  
           [0012]    Briefly summarized, the claimed invention includes a processor, a display device that displays output of the processor, a communications module that communicates with a computer, and an expansion slot that can accept an expansion card. When the communications module is in a first mode the communications module allows communication between the expansion slot and the processor and prevents communication between the expansion slot and the computer. When the communications module is in a second mode the communications module allows communication between the expansion slot and the computer and prevents communication between the expansion slot and the processor. Also provided are third and fourth modes that respectively prevents communication between the expansion slot and the processor or the computer, and allows communication between the expansion slot and both the processor and computer.  
           [0013]    According to the claimed invention, the claimed invention further includes a connection port and a wireless communications module. The mode of the communications module can be set by the communications module detecting states of the connection port, wireless communications module, and expansion slot. Alternatively, the mode of the communications module can be set by the processor and the computer.  
           [0014]    It is an advantage of the claimed invention that the communications module has up to four modes and as a result provides direct access to the expansion card to both the portable computer and the computer.  
           [0015]    It is a further advantage of the claimed invention that the resources of the expansion card can be used by both the portable computer and the computer.  
           [0016]    These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0017]    [0017]FIG. 1 is a perspective view of a prior art portable computer and expansion card.  
         [0018]    [0018]FIG. 2 is a block diagram of the portable computer of FIG. 1.  
         [0019]    [0019]FIG. 3 is a block diagram of a portable computer according to the preferred embodiment of the present invention.  
         [0020]    [0020]FIG. 4 is a block diagram of the communications module of FIG. 3 in a second mode.  
         [0021]    [0021]FIG. 5 is a block diagram of a second embodiment of the communications module shown in FIG. 3. 
     
    
     DETAILED DESCRIPTION  
       [0022]    A portable computer  40  according to the preferred embodiment of the present invention is shown in FIG. 3. The portable computer  40  comprises a processor  42  and a memory  44  for providing functions such as controlling a user interface  46 . The user interface includes a display device  48 , commonly a liquid crystal display (LCD), and an input device  50 , which can be any number of devices such as a touch screen component of the LCD  48 , a keyboard, or a touch pad. Connected to the processor  42  is a communications module  51 . The communications module  51  serves to manage the flow of data between the processor  42  and a connection port  54 , a wireless communications module  56 , and an expansion slot  58 . The connection port  54  is used to connect the portable computer  40  with another computer  60  so that information can be exchanged. The wireless communications module  56  serves the same purpose as the connection port  54 , except that the wireless communications module  56  communicates with the computer  60  using electromagnetic signals  62  according to a wireless local area network (LAN) standard such as that set by IEEE 802.11b. The expansion slot  58  can accept an expansion card  64 , which delivers added functionality to the portable computer  40  such as additional flash memory, a peripheral interface, or a network interface. For the purposes of this detailed description the expansion slot  58  is a secure digital (SD) expansion slot, and the expansion card  64  is an SD flash memory card, but both should not be construed to be limited to such. Of course, the portable computer  40  comprises additional components, however, these will not be described here as it is well known in the art and is extraneous to the detailed description of the preferred embodiment.  
         [0023]    The communications module  51  comprises a switch circuit  52  and a detection circuit  53 . The switch circuit  52  shown in FIG. 3 is shown simplified for illustrative purposes. In practical application and as well known in the art, the switch circuit  52  can be realized by employing an integrated circuit (IC) I/O bus. Similarly, the detection circuit  53  is shown only schematically and can also be realized using an IC chip. Naturally, the switch circuit  52  and the detection circuit  53  can be combined into a single circuit that can be disposed on a single IC chip.  
         [0024]    The detection circuit  53  detects states of the connection port  54 , the wireless communications module  56 , and the expansion slot  58  and controls the switch circuit  52  accordingly. For instance, the detection circuit  53  as shown in FIG. 3 has detected that the connection port  54  is not connected to the computer  60  and that the wireless communications module  56  is active. This is interpreted as the portable computer  40  being used in a portable manner, that is, disconnected from the computer  60 . Accordingly, the detection circuit  53  controls the switch circuit  52  to connect the expansion slot  58  to the processor  42  and connect both the connection port  54  and the wireless communications module  56  to the processor  42 . Hence, potential communication between the connection port  54  or wireless communications module  56  and the expansion slot  58  is regulated by the processor  42 . For that reason, the computer  60  cannot directly access or issue commands to the expansion slot  58 , and in effect, the resources of the flash memory card  64  are controlled by the processor  42 . This first mode of the communications module  51  allows the processor  42  to control the resources of the expansion card  64 .  
         [0025]    A second mode of the communications module  51  is shown in FIG. 4. Also shown in FIG. 4 are switches  52   c ,  52   w , and  52   p  of the switch circuit  52 . In the second mode, the detection circuit  53  has detected that the connection port  54  is connected to the computer  60  and that the wireless communications module  56  is not active. This is interpreted as the portable computer  40  being used in combination with the computer  60 , and connected to the computer  60  through a cradle or similar apparatus. Accordingly, the detection circuit  53  controls the switch circuit  52  to set switch  52   p  so that expansion slot  58  is disconnected from processor  42  and set switches  52   c  and  52   w  so that both the connection port  54  and the wireless communications module are connected to the expansion slot  58 . Consequently, there is direct communication by both the connection port  54  and wireless communications module  56  with the expansion slot  58 . As a result, the computer  60  can directly access and issue commands to the expansion slot  58 , and in effect, the resources of the flash memory card  64  are controlled by the computer  60 .  
         [0026]    A third mode is defined as setting the switches  52   c ,  52   w , and  52   p  as open to disconnect all of the processor  42 , the connection port  54 , and the wireless communications module  56  from the expansion slot  58 . This is can be used if the flash memory card  64  is removed from the expansion slot  58 . The third mode is entered when the communications module  51  detects that the expansion slot  58  is empty.  
         [0027]    Referring to FIG. 3, a user wants to utilize the portable computer  40  wirelessly, that is, not connected to the computer  60 . To do this, the user disconnects the connection port  54  from the computer  60 . The detection circuit  53  detects that the connection port  54  is inactive and controls the switch circuit to connect the expansion port  58  to only the processor  42 . At this time, the user can still access the computer  60  through the wireless communication module  56 . However, the resources of the flash memory card  64  are controlled by the processor  52 .  
         [0028]    When the user wishes to utilize the portable computer  40  connected to the computer  60 , the user connects the connection port  54  to the computer  60  via a cradle, cable, or similar connection apparatus. The detection circuit  53  detects that the connection port  54  is active and controls the switch circuit  52  to set the switches  52   c ,  52   w , and  52   p  as shown in FIG. 4. The portable computer  40  now allows direct access to the expansion slot  58  and the resources of the flash memory card  64  by the computer  60  and prevents direct access to the flash memory card  64  by the processor  42 . In other words, the user can use the computer  60  to directly access the flash memory card  64 .  
         [0029]    Consider a second embodiment of the communications module  51 ″ as illustrated in FIG. 5. The communications module  51 ″ comprises the switch circuit  52 , but does not include a detection circuit. Rather, the processor  42 , the connection port  54 , and the wireless communications module  56  control the setting of the switches  52   c ,  52   w , and  52   p  of the switch circuit  52 . The switches  52   c ,  52   w , and  52   p  can be set to give the communications module  51 ″ all three of the previously described modes, namely the first mode, the second mode, and the third mode.  
         [0030]    In the second embodiment, the communications module  51 ″ accepts commands from the processor  42 , the connection port  54 , and the wireless communications module  56  and changes modes accordingly. Hence, the computer  60  and the processor  42  must cooperate to determine how the resources of the flash memory card  64  are to be accessed. The processor  42  and the computer  60  have shared direct control over the resources of the flash memory card  64 . In fact, the resources of the flash memory card  64  are more tightly controlled in the second embodiment. While the second embodiment is less automatic than the preferred embodiment, the desired result is still achieved.  
         [0031]    A fourth mode of the communications module  51  is also provided for by the second embodiment. In the fourth mode, the switches  52   c ,  52   w , and  52   p  are all set to closed so that both the computer  60  and the processor  42  have direct access to the expansion slot  58 . In the fourth mode, the resources of the flash memory card  64  are available to both the computer  60  and the processor  42 . Negotiation for and distribution of the resources of the flash memory card  64  are performed by both the computer  60  and the processor  42 . As mentioned previously, the switches  52   c ,  52   w , and  52   p  are in practical application IC circuits and are shown as simplified single-input-single-output switches for explanatory purposes only.  
         [0032]    Naturally, other combinations of the settings of the switches  52   c ,  52   w , and  52   p  and corresponding modes of the switch circuit  52  are possible. These additional modes of the switch circuit  52  are inherent to the design of the switch circuit  52  and do not add any unexpected functionality over the four modes already described.  
         [0033]    For both the preferred and second embodiments, the connection port  54  can be redundant, and the wireless communications module  56  can be the only means for communicating with the computer  60 , the state of wireless communications module  56  being detected by the communications module  51  in the preferred embodiment. Likewise, the present invention portable computer  40  need not comprise the wireless communications module  56 , the state of the connection port  54  being detected by the communications module  51  in the preferred embodiment as described.  
         [0034]    Other embodiments, such as an embodiment allowing the switch circuit  52  to be controlled by both the detection circuit  53  and the processor  42 , are also possible by applying the teachings of the present invention.  
         [0035]    In contrast to the prior art, the present invention communications module allows direct access to an expansion slot and corresponding expansion card by both a processor of a portable computer and another computer. The present invention also provides modes of the communications module that can be either automatically switched or controlled. Thus, the resources of the expansion card can be used by both the portable computer and the other computer.  
         [0036]    Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.