Abstract:
A connection device for a cable to selectively retrieve electrical signals in a is provided. The connection device is connected to a first unit and a second unit, and includes a first conductive wire set and a second conductive wire set. During debugging or testing, one plugs the cable in the connection device to separate the first conducive wire set and the second conductive wire set so that the signals coming from either the first unit or the second unit can be retrieved separately.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
         [0001]    This Application claims priority to Taiwan Patent Application No. 092112742 filed on May 9, 2003.  
         FIELD OF INVENTION  
         [0002]    The present invention relates to a connection device of a for a retrieval device to selectively retrieve electrical signals.  
         BACKGROUND OF THE INVENTION  
         [0003]    With the progress of integrated circuit manufacture techniques, more and more integrated circuits can fit into one single . However, this increases the complexity of the circuit layout and signal transmission. To ensure the stability and accuracy of the system, testing before use becomes important.  
           [0004]    To facilitate testing, the system is generally divided into several units based on their functionality and each of the units is electrically connected to others to transmit signals. During testing, one can isolate one of the units by cutting off the connections between it and the others, for example, to retrieve only the signals from the specific unit to determine its functionality without signal interference coming from other units. FIG. 1 shows an example. The system  1  includes two units, a first unit  101  and a second unit  103 , with connections in between to transmit signals. When manufacturing the system  1 , one can embed a signal retrieval device  105 , a first resistor array  107  and a second resistor array  109  to facilitate retrieving signals from either the first unit  101  or the second unit  103 . The signal retrieval device  105  is configured to connect to a cable for retrieving the signals flowing through the signal retrieval device  105 . It is noted that signals can be transmitted between the first unit  101  and the second unit  103  without plugging the cable if the connections are not cut off The first resistor array  107 , having zero resistivity, is embedded between the first unit  101  and the signal retrieval device  105 . The second resistor array  109 , having zero resistivity, is embedded between the second unit  103  and the signal retrieval device  105 .  
           [0005]    If one needs to retrieve the signals of the first unit  101 , the second resistor array  109  will be cut off so that the signals of the second unit  103  cannot reach the signal retrieval device  105 . Once a cable is plugged into the signal retrieval device  105 , only the signals from the first unit  101  will be retrieved and therefore one can test the functionality of the first unit  101  without signal interference from the second unit  103 . Similarly, one can retrieve the signals of the second unit  103  by cutting of the first resistor array  107  and thereby determine the functionality of the second unit  103 .  
           [0006]    It is however a complicated process to cut off the first resistor array  107  or the second resistor array  109  for testing. Moreover, after testing, the first resistor array  107  or the second resistor array  109  needs to be welded back before the system  1  can function normally. Hence, using the structure of the signal retrieval device  105 , the first resistor array  107  and the second resistor array  109  for testing is costly and time-consuming.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention provides a connection device for a retrieval device to selectably retrieve an electrical signal while testing or debugging, and a system with such a connection device. The connection device, connected to a first unit and a second unit, includes a first conductive wire set and a second conductive wire set. The first conductive wire set has a first end and a second end, wherein the first end is electrically connected to the first unit. The second conductive wire set also has a first end and a second end, wherein the first end of the second conductive wire set is electrically connected to the second unit. When the retrieval device is not plugged in the connection device, the second end of the first conductive wire set and the second end of the second conductive wire set are electrically connected so that the first unit and the second unit are electrically connected, which means signals can be transmitted between the first unit and the second unit. When the retrieval device is plugged in the connection device for testing or debugging, the retrieval device separates the second end of the first conductive wire set and the second end of the second conductive wire set to retrieve electrical signals coming from either the first unit or the second unit. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 illustrates an example of the connection device of the prior art;  
         [0009]    [0009]FIG. 2A illustrates a lateral view of a first embodiment of the present invention;  
         [0010]    [0010]FIG. 2B illustrates a pictorial drawing of the first embodiment of the present invention;  
         [0011]    [0011]FIG. 3 illustrates a lateral view of a second embodiment of the present invention;  
         [0012]    [0012]FIG. 4A illustrates a pictorial drawing of a third embodiment of the present invention; and  
         [0013]    [0013]FIG. 4B illustrates a lateral view of the third embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0014]    [0014]FIG. 2A and FIG. 2B illustrate one embodiment of the present invention. The connection device  2  is connected to a first unit  101  and a second unit  103 , and includes a first conductive wire set  201  and a second conductive wire set  203 . The first unit  101  and the second unit  103  are included in the same system but are divided according to their functionalities. Both the first conductive wire set  201  and the second conductive wire set  203  are arc-shaped. The first conductive wire set  201  has a first end  205  and a second end  207 , wherein the first end  205  is electrically connected to the first unit  101  by weld. The second conductive wire set  203  has a first end  209  and a second end  211 , wherein the first end  209  is electrically connected to the second unit  103  by welding. In this embodiment, at least one of the second end  207  of the first conductive wire set  201  and the second end  211  of the second conductive wire set  203  is elastic and such that ends  207 ,  211  are able to contact each other in the way as FIG. 2A and FIG. 2B show.  
         [0015]    The connection device  2  is capable of receiving a retrieval device. In the first embodiment, it is a flexible flat cable  213  including a signal line  215  for transmitting signals on one side and a flexible plastic insulator  217  for insulation on the other side.  
         [0016]    When the cable  213  is not plugged in the connection device  2 , the second end  207  of the first conductive wire set  201  and the second end  211  of the second conductive wire set  203  contact with each other, which means they are electrically connected. In other words, the first unit  101  and the second unit  103  are electrically connected as well so signals may be transmitted between the first unit  101  and the second unit  103 .  
         [0017]    When the cable  213  is plugged in the connection device  2  in the direction as FIG. 2A shows, the cable  213  separates the second end  207  of the first conductive wire set  201  and the second end  211  of the second conductive wire set  203 . Hence, the signal line  215  contacts the second end  207  of the first conductive wire set  201 , and the flexible plastic insulator  217  contacts the second end  211  of the second conductive wire set  203 . Now the signals of the first unit  101  can go through the cable  213 , but the signals of the second unit  103  are blocked by the flexible plastic insulator  217 . The other end of the cable  213  might be connected to a signal analyzer or the like so it can determine the functionality of the first unit  101  without signal interference from the second unit  103 .  
         [0018]    If, instead of the first unit  101 , it is the second unit  103  that needs to be tested, one simply reverses the cable  213  and plugs it in the connection device  2 . Now the signal line  215  contacts the second end  211  of the second conductive wire set  203  and the flexible plastic insulator  217  contacts the second end  207  of the first conductive wire set  201 . The signals of the second unit  103  can go through the cable  213 , but the signals of the first unit  101  are blocked by the flexible plastic insulator  217 . Therefore, the signal analyzer can determine the functionality of the second unit  103  without signal interference from the first unit  101 .  
         [0019]    The connection device  2  further includes a casing  219  for receiving the first conductive wire set  201  and the second conductive wire set  203 . The casing  219  has an opening  221  for the cable  213  to be plugged in the connection device  2 .  
         [0020]    The retrieval device of the present invention is not limited to a flexible flat cable set forth in the first embodiment. It might be, for example, a device with conductive wires appropriately arranged on a circuit board, or a probe with a conductor on one side and an insulator on the other side. Moreover, the retrieval device might be designed as the cable  213  of the first embodiment with two signal lines  215  on both sides respectively connected to the first unit  101  and the second unit  103 . It is noted that the two signal lines  215  do not contact with each other. When the retrieval device is plugged in the connection device  2 , the signals of the first unit  101  and the second unit  103  can be retrieved at the same time via the cable  213  without interfering with each other.  
         [0021]    The first conductive wire set  201  and the second conductive wire set  203  do not need to be arc-shaped as set forth above. A second embodiment of the present invention includes a first conductive wire set  201  and the second conductive wire set  203  shaped in such a way as shown in FIG. 3. When the cable  213  is plugged in the connection device  2 , the second end  207  of the first conductive wire set  201  and the second end  211  of the second conductive wire set  203 , both of which are elastic, are separated by the cable  231  so either the signals of the first unit  101  or the signals of the second unit  103  can be transmitted out.  
         [0022]    [0022]FIG. 4A and FIG. 4B show a third embodiment of the present invention. When the cable  213  is not plugged in the connection device  2 , the first conductive wire set  201  and the second conductive wire set  203  are electrically connected via a conductive medium  401  which has an insulation part  403  and a conduction part  405 . The first conductive wire set  201  and the second conductive wire set  203  are movably in contact with conduction part  405 , i.e. the conduction part  405  merely comes in contact with the surfaces of the first conductive wire set  201  and the second conductive wire set  203 ; it is not welded to or fixed on the surfaces. The insulation part  403  is configured to separate the elements of the conduction part  405  to avoid shortage. In addition, the third embodiment includes two openings: a first opening  407  and a second opening  409 .  
         [0023]    When the signals of the first unit  101  are to be retrieved, a cable  411  is plugged in the first opening  407  and then forces the second end  207  of the first conductive wire set  201  to bend downwards in order to separate the conduction part  405  and the second end  207  of the first conductive wire set  201 . Only the signals of the first unit  101  will be retrieved from a conductive tip  413  of the cable  411 . Similarly, when the signals of the second unit  103  are to be retrieved, a cable  411  is plugged in the second opening  409  and forces the second end  211  of the second conductive wire set  203  to bend downwards in order to separate the conduction part  405  and the second end  211  of the second conductive wire set  203 . Only the signals of the second unit  103  will be retrieved from the conductive tip  413  of the cable  411 .  
         [0024]    According to the present invention, the connection device can retrieve signals separately without damaging system structures. Moreover, the test cables or probes of the prior art are useful for the connection device of the present invention so there is no new cable or probe required for the connection device.  
         [0025]    The present invention also provides a system for a flexible flat cable to selectably retrieve electrical signals. The flexible flat cable has been described above. The includes a first unit, a second unit, and a connection device, all of which are also described above.