Abstract:
A two-way connectivity USB control device and its operation method are disclosed. The present invention solves a problem of the prior art that requires users to manually switch a USB controller between an active mode and a passive mode and set a predetermined time interval as in prior art. The two-way connectivity USB control device detects whether or not there is a voltage input. If the detection result is yes, then the two-way connectivity USB control device is switched to a transmit mode, or else the two-way connectivity USB control device is switched to a transparent mode for accessing data stored in an external device by issuing a control command directly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the invention 
         [0002]    The present invention relates to a USB control device and its operation method, and more particularly to a USB control device and its operation method with a two-way connectivity embedded into a computer system. 
         [0003]    2. Description of Related Art 
         [0004]    Since the USB specification has the advantages of a plug-and-play function for connecting up to 127 USB devices, supplying a power of 5V, and occupying only one IRQ, the USB are used extensively by users. In existing computer systems, at least one USB port is provided for connecting external devices, and thus manufacturers adopts the concept of transmitting data between computers via a USB interface. 
         [0005]    Since the USB interface is of master/client architecture, a data transmission between a computer and a peripheral is performed by a master function provided by the computer and a device function provided by the peripheral. 
         [0006]    Therefore, some manufacturers integrate a bridge chip and a USB connecting line to form a USB connecting line with a bridge function, but such arrangement requires a bridge chip and thus incurs a higher cost, and the connecting line with the bridge function is only for a connection between computers. If it is necessary to connect a general USB device, a general USB connecting line is required, and thus the application is very inconvenient. 
         [0007]    To solve the foregoing problem, related patents including R.O.C. Pat. No. M276282 entitled “Switching USB access device” are disclosed, and the USB access device  1  of such patent as shown in  FIG. 1  comprises a USB interface unit  10 , a USB controller  12 , a function module  14  and a manual switch  16 . 
         [0008]    The function module  14  can be a memory for storing an active mode driver  140  and a passive mode driver  142 , and the manual switch  16  is used for setting up the USB controller  12  to execute the active mode driver or the passive mode driver, and the USB controller  12  is switched to an active mode or a passive mode. 
         [0009]    Further, R.O.C. Pat. No. 591509 entitled “USB control circuit applicable for computer transmissions and operation method thereof” is disclosed, and the USB control circuit of this patent comprises a server controller with a USB interface, a device function circuit and a path switching device, provided for users to specify or automatically detect a data transmission between computers. Users specify a connecting path of the path switching device according to the user&#39;s desired connecting peripheral device or according to a computer that would automatically decide on a connecting path, and the automatic decision preset a USB control circuit to be the default active mode, then according to the preset time interval used for setting up a USB control circuit the prior art automatically decide to operate by the active mode or by the device function mode. 
         [0010]    When the aforementioned R.O.C. Pat. No. M276282 is practiced, it is necessary to add the manufacturing cost for installing a manual switch on the USB access device, and a user must manually switch to the desired operation mode when a switch is required. Thus, the application is very inconvenient and inefficient to users. The following shortcomings are found in the practice of the R.O.C. Pat. No. 591509. Firstly, the user specified way incurs a higher manufacturing cost for adding a switch. Secondly, an active mode is used for the initial state of the USB control circuit, and a predetermined time interval is used for switching a mode, and thus the setting of timing in the software must be very accurate. If the response time of a connected device exceeds the predetermined time interval, an uncertain status will occur. 
       SUMMARY OF THE INVENTION 
       [0011]    In view of the foregoing shortcomings of the present invention, the inventor of the present invention provides a two-way connectivity USB control device and operation method thereof to determine whether or not the USB control device is switched to a transparent mode or a transmission mode by detecting the voltage. Transparent mode here means the data coming in from one end of the present invention device, such as a first USB port, is not translated and passes directly to the other end of the present invention device, such as a second USB port. While in the transparent mode, the two-way connectivity USB control device acts like a connector between two devices. 
         [0012]    Therefore, it is a primary objective of the present invention to overcome the shortcomings of the prior art by providing a two-way connectivity USB control device and its operation method in accordance with the present invention. 
         [0013]    To achieve the foregoing objective, the present invention provides a two-way connectivity USB control device, and the two-way connectivity USB control device is embedded into a computer system and comprises: a first USB control unit, electrically coupled to a first USB electronic switch portion; a second USB control unit, electrically coupled to a second USB electronic switch portion; a direction selection unit, electrically coupled to the first USB electronic switch portion and the second USB electronic switch portion, for selecting a data transmission direction between the first USB control unit and the second USB control unit; a memory unit, containing a firmware program code; and a microcontroller unit, electrically coupled to the memory unit, the first USB control unit and the second USB control unit, for carrying out a data transmission between the first USB control unit and the second USB control unit through the USB format contained in the firmware program code. 
         [0014]    The present invention further provides an operation method of a two-way connectivity USB control device, and the two-way connectivity USB control device is electrically coupled to a computer system through a first USB port, and a second USB port is electrically coupled to an external device, and the operation method comprises the steps of: detecting whether or not there is a voltage input at the second USB port; switching a first USB electronic switch portion and a second USB electronic switch portion of the two-way connectivity USB control device to a transmission mode; transmitting a control command issued by the second USB port to the first USB port; declaring the computer system in an optical disk mode according to the control command; transmitting a path file information to the computer system and the external device; waiting for an operation control command transmitted from the computer system or the external device; determining whether or not the operation control command is a file transmission command; and executing a file transmission operation between the computer system and the external device. 
         [0015]    The two-way connectivity USB control device and operation method thereof of the present invention can overcome the shortcomings of prior art, the present invention provides a voltage detection method to solve the problem of the R.O.C. Pat. No. 591509 that produces an uncertain status when the response time of the connected device exceeds a predetermined time interval, and the USB control device does not have any switch, and thus saving the manufacturing cost of producing the switch. 
         [0016]    To make it easier for our examiner to understand the expected effect, technical measure and performance of the present invention, we use a preferred embodiment accompanied with related drawings for the detailed description of the present invention as follows. However, the drawings are primarily for the reference and illustration purposes only, but not intended for limiting the scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a schematic view of a USB access device of a prior art; 
           [0018]      FIG. 2  is a schematic view of a two-way connectivity USB control device in accordance with the present invention; 
           [0019]      FIG. 3  is a schematic view of a computer system applying a two-way connectivity USB control device in accordance with the present invention; and 
           [0020]      FIG. 4  is a flow chart of a method of applying a two-way connectivity USB control device in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Referring to  FIG. 2  for a schematic view of a two-way connectivity USB control device in accordance with the present invention, the two-way connectivity USB control device  2  comprises a memory unit  20 , a microcontroller unit  22 , a direction selection unit  24 , a first USB control unit  26 , a second USB control unit  28 , a first USB electronic switch portion  30 , a second USB electronic switch portion  32 , a first USB port  34  and a second USB port  36 . 
         [0022]    In  FIG. 2 , the first USB control unit  26  is electrically coupled to an end of the first USB electronic switch portion  30 , and another end of the first USB electronic switch portion  30  is electrically coupled to the first USB port  34 . An end of the second USB control unit  28  is electrically coupled to the second USB electronic switch portion  32 , and another end of the second USB electronic switch portion  32  is electrically coupled to second USB port  36 . The first USB electronic switch portion  30  and second the USB electronic switch portion  32  are activated for switching if a voltage inputted from the first USB port  34  and the second USB port  36  is inputted. 
         [0023]    The direction selection unit  24  is electrically coupled to the first USB electronic switch portion  30  and the second USB electronic switch portion  32  for selecting a data transmission direction between the first USB control unit  26  and the second USB control unit  28 , and the interior of the direction selection unit  24  includes a voltage detection circuit (not shown in the figure) for detecting whether or not the first USB electronic switch portion  30  or the second USB electronic switch portion  32  has a voltage input, and the voltage detection circuit is comprised of a diode and a voltage comparator. 
         [0024]    The memory unit  20  includes a firmware program code, and the firmware program code contains commands coded in the USB format, and the memory unit  20  is a flash memory or any other non-volatile memory. The microcontroller unit  22  is electrically coupled to the memory unit  20 , the first USB control unit  26  and the second USB control unit  28 . With the USB format of the firmware program code, data are transmitted between the first USB control unit  26  and the second USB control unit  28  in the USB format. 
         [0025]    The method of applying the two-way connectivity USB control device of the present invention is described as follows. The first USB port  34  of the two-way connectivity USB control device is connected with a computer system, and the second port  36  is connected with an external device, such that if the external device connected to the second USB port  36  supplies a voltage input, the voltage detection circuit installed in the direction selection unit  24  will detect the voltage input, and the direction selection unit  24  will switch an electronic switch originally connecting Point A of the first USB electronic switch portion  30  and Point B of the second USB electronic switch portion  32  to instead connecting Point A′ of the first USB electronic switch portion  30  and Point B′ of the second USB electronic switch portion  32  respectively (the above described operation is the transparent function). If the external device connected to the second USB port  36  issues a control command, the microcontroller unit  22  will transmit the control command to the first USB port  34  according to the USB format of the firmware program code, and an application program installed in the computer system will carry out the related file transmission function. 
         [0026]    Referring to  FIG. 3  for a schematic view of a computer system applying a two-way connectivity USB control device in accordance with the present invention, the two-way connectivity USB control device is integrated into a system on a chip and embedded into a computer system or an electronic device, and the system comprises a two-way connectivity USB control device  2 , a Southbridge chipset  4 , a bus interface  40 , a USB data transmission line  38  and an external device  3 . 
         [0027]    Of course, a computer system does not simply have an electronic component such as the Southbridge chipset  4  only, but those skilled in the art know that the computer system also includes a memory, a floppy disk drive, a hard disk, a Northbridge chipset, a bus slot, and a central processing unit and other components, wherein the hard disk stores a software program, but these are outside the scope of the present invention. 
         [0028]    The two-way connectivity USB control device  2  comprises a memory unit  20 , a microcontroller unit  22 , a direction selection unit  24 , a first USB control unit  26 , a second USB control unit  28 , a first USB electronic switch portion  30 , a second USB electronic switch portion  32 , a first USB port  34  and a second USB port  36 . The first USB port  34  of the two-way connectivity USB control device  2  is electrically coupled with the Southbridge chipset  4  through the bus interface  40 , and the bus interface  40  can support PCI or PCI extended interface, and the two-way connectivity USB control device  2  can be integrated into the interior  5  of the computer system to become a part of the computer system. In addition, the second USB port  36  of the two-way connectivity USB control device  2  is electrically coupled to the external device  3  through the USB data transmission line  38 , and the USB data transmission line  38  is a general USB cable available in the market, and the external device  3  can be a computer system or a USB device without a power supply. 
         [0029]    Referring to  FIGS. 3 and 4 ,  FIG. 4  shows a flow chart of a method for applying the two-way connectivity USB control device in accordance with the present invention, the two-way connectivity USB control device  2  is electrically coupled to the Southbridge chipset  4  of the computer system through the bus interface  40  and through the first USB port  34 , and the second USB port  36  is electrically coupled to the external device  3 . The operation method comprises the following steps. 
         [0030]    In Step (S 100 ), the step detects whether or not the external device  3  supplied a voltage input from the second USB port  36  through the USB data transmission line  38  (S 100 ), wherein the detection is done by a voltage detection circuit installed in the direction selection unit  24 . In an initial state, the first USB electronic switch portion  30  and the second USB electronic switch portion  32  of the invention are electronic switches that completes the connecting at Points A and at B respectively. 
         [0031]    In the detection step (S 100 ), if the voltage detection circuit detects a voltage input, the two-way connectivity USB control device  2  will switch the first USB electronic switch portion  30  and the second USB electronic switch portion  32  to a transmission mode (S 102 ). In other words, the electronic switches of the first USB electronic switch portion  30  and the second USB electronic switch portion  32  are switched from Points A and B to Points A′ and B′ respectively. Now, we know that the external device  3  is a device with an active power supply such as a computer system. On the other hand, if the voltage detection circuit has not detected a voltage input in the detection step (S 100 ), then the first USB electronic switch portion  30  and the second USB electronic switch portion  32  of the two-way connectivity USB control device will be in a transparent mode (S 104 ). In other words, the initial state of the first USB electronic switch portion  30  and the second USB electronic switch portion  32  is maintained. 
         [0032]    In Step (S 104 ), the voltage detection circuit has not detected a voltage input, indicating that the external device  3  is a device with a passive power supply such as a USB flash or another storage device. After the step (S 104 ), the first USB electronic switch portion  30  and the second USB electronic switch portion  32  of the two-way connectivity USB control device are in a transparent mode. In other words, the first USB port  34  and the second USB port  36  are connected directly, and the computer system can issue a control command directly to the external device  3 . For example, a user issues a data control command to an input device (such as a keyboard or a mouse) of a computer system, so that the computer system can access the data stored in the external device  3 . 
         [0033]    After the Step (S 102 ), the external device  3  will transmit a control command issued by the external device  3  to the first USB port  34  through the second USB port  36  (S 106 ). Now, the microcontroller unit  22  of the two-way connectivity USB control device  2  will activate a firmware program code stored in the memory unit  20 , wherein the firmware program code contains a command coded in a USB format, and the control command is packaged into a control command in the USB format, and the packaged control command is transmitted by the first USB port  34  to the computer system through the bus interface  40 , and the computer system includes a software program such that after the computer system receives the packaged control command, the software program of the computer system will declare the computer system to be in an optical disk mode according to the packaged control command (S 108 ), and inform the external device  3  that the computer system is in the optical disk mode. 
         [0034]    The computer system will transmit an optical disk driver image file to the second USB port  36  through the first USB port  34  (S 110 ). After the optical disk driver image file is received by the external device  3  and stored into a memory, the external device  3  immediately execute an automatic application program contained in the optical disk driver image file (S 112 ). With the automatic execution of the application program, the computer system transmits a path file information to the external device  3  and displays the information on a display screen of the computer system and a display screen of the external device  3  respectively (S 114 ). Wait for an operation control command transmitted from the computer system or the external device  3  (S 116 ). If the computer system or the external device  3  sends out the operation control command, the computer system or the external device  3  will determine whether or not the operation control command is a file transmission command (S 118 ). If the determination result is negative, then return to the step of waiting for an operation control command transmitted from the computer system or transmitted from the external device  3  (S 116 ). If the determination result is affirmative, then execute the file transmission operation between the computer system and the external device  3  (S 120 ). Finally after step (S 120 ), the two-way connectivity USB control device determines whether or not the external device  3  is detached from the second USB port  36  (S 122 ). If the determination result is affirmative, the whole operation procedure will be ended. On the other hand, if the determination result is negative, return to the step of waiting for an operation control command transmitted from the computer system or the external device  3  (S 116 ). 
         [0035]    Unlike the R.O.C. Pat. No. 591509, the two-way connectivity USB control device of the present invention has no manual switch, and the present invention simply uses the existence of a voltage input as the determination condition to drive the electronic switches of the first USB electronic switch portion and the second USB electronic switch portion for the switching process, and thus the present invention does not have the drawbacks of the R.O.C. Pat. No. 591509. Such that if the response time of a connected device exceeds a predetermined time interval, an uncertain status will occur. The method of operating the two-way connectivity USB control device in accordance with the present invention can display the path file information on the computer system and the external device simultaneously for the file transmission function. 
         [0036]    Although the present invention has been described with reference to the preferred embodiments thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.