Abstract:
A motherboard includes a first CPU module including a first CPU slot and a first memory slot, a first north bridge circuit coupled to the first CPU module, a second CPU module including a second CPU slot and a second memory slot, a second north bridge circuit coupled to the second CPU module, a south bridge circuit coupled to the first north bridge circuit and the second north bridge circuit, and a selection circuit coupled to the south bridge circuit for coupling a north bridge circuit corresponding to a CPU slot containing a CPU to the south bridge circuit.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a motherboard allowing selection of different central processing units, and more particularly, to a motherboard allowing use of different central processing units through the installation of a plurality of north bridge circuits corresponding to the central processing units.  
         [0003]     2. Description of the Prior Art  
         [0004]     A central processing unit (CPU) is one of the most important factors affecting the efficiency of a computer system. These days, the CPUs produced by Intel and Advanced Micro Device (AMD) dominate the market. However, since the Intel Pentium II entered the market, interfaces of a variety of CPUs produced by manufacturers are no longer compatible. In the years of the 486 and 586, AMD, Intel, and Cyrix chips all supported the same CPU interface (CPU slot), so it was very convenient for a user to change to a CPU of another brand.  
         [0005]     However, these days CPUs produced by different manufacturers not only require different interfaces (slots), the chipsets functioning together with the CPUs also differ from one another even when the CPUs are produced by the same manufacturer. For example, the interfaces of CPUs produced by Intel include Socket 478, Socket 604, Socket 775, etc., and the interfaces of CPUs produced by AMD include Socket A, Socket 754, Socket 939, Socket 940, etc.  
         [0006]     A north bridge circuit and a south bridge circuit are two core components of a conventional personal computer structure. The south bridge circuit processes input and output functions of the system (for example, data exchange between hard disks and external devices). The north bridge circuit controls high-speed communications between system processors, graphics sub-systems, memory, and peripheral component interface (PCI) buses. Since CPUs of different brands transmit differently formatted signals, the north bridge circuits for different CPUs are themselves different from one another. CPUs of different brands not only require different interfaces, their corresponding chipsets are also different. Therefore, if the CPU is changed, the motherboard has to be changed accordingly. This wastes resource and increases the burden on consumers.  
       SUMMARY OF THE INVENTION  
       [0007]     It is therefore a primary objective of the claimed invention to provide a motherboard allowing selection of different central processing units.  
         [0008]     The motherboard includes a first CPU module comprising a first CPU slot and a first memory slot, a first north bridge circuit coupled to the first CPU module, a second CPU module comprising a second CPU slot and a second memory slot, a second north bridge circuit coupled to the second CPU module, a south bridge circuit coupled to the first north bridge circuit and the second north bridge circuit, and a selection circuit coupled to the south bridge for coupling the south bridge circuit either to the first north bridge circuit when a CPU is inserted into the first CPU slot of the first CPU module, or to the second north bridge circuit when a CPU is inserted into the second CPU slot of the second CPU module.  
         [0009]     The present invention further discloses a motherboard, which includes a first CPU module comprising a first CPU slot and a first memory slot, a first north bridge circuit coupled to the first CPU module, an interface circuit for insertion of a CPU interface card, a south bridge circuit coupled to the first north bridge circuit and the interface circuit, and a selection circuit coupled to the south bridge for coupling the south bridge circuit to either of the first north bridge circuit and the interface circuit according to signals of the interface circuit and the first north bridge circuit.  
         [0010]     The present invention further discloses a motherboard, which includes an interface circuit for engaging with a CPU interface card, and a south bridge circuit coupled to the interface circuit.  
         [0011]     Through the use of the motherboards of the present invention, a user can select different CPUs according to the CPU interface cards, and hereby achieve the object to install a variety of CPUs on an identical motherboard.  
         [0012]     These and other objectives of the present 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 THE DRAWINGS  
       [0013]      FIG. 1  is a block diagram of a motherboard allowing selection of different central processing units of a first embodiment according to the present invention.  
         [0014]      FIG. 2  is a block diagram of a motherboard allowing selection of different central processing units of a second embodiment according to the present invention.  
         [0015]      FIG. 3  is a block diagram of a motherboard allowing selection of different central processing units of a third embodiment according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0016]     In a computer system, a south bridge circuit processes input and output functions of the system (for example data exchange between hard disks, external devices), and a north bridge circuit controls high-speed communications between system processors, graphics sub-systems, memory, and peripheral component interface (PCI) buses. Thus, north bridge circuits for use with different CPUs differ from one another, while south bridge circuits can be the same. The present invention provides, in an identical platform (motherboard), a south bridge circuit and a variety of north bridge circuits corresponding to different CPUs, so as to achieve the object of allowing installation of different central processing units.  
         [0017]     Please refer to  FIG. 1 , which is a block diagram of a motherboard  100  allowing selection of different central processing units of a first embodiment according to the present invention. The motherboard  100  comprises a first CPU module  102 , a second CPU module  104 , a first north bridge circuit  106 , a second north bridge circuit  108 , a selection circuit  110 , a south bridge circuit  112 , a first graphics card interface  124 , a second graphics card interface  126 , a peripheral interface  114 , a clock circuit  130 , a clock conversion circuit  132 , and a peripheral device  128 . The first CPU module  102  comprises a first CPU slot  116  and a first memory slot  118 . The second CPU module  104  comprises a second CPU slot  122  and a second memory slot  120 . The first CPU slot  116  has a type different from that of the second CPU slot  122 , both of which are installed to receive CPUs of different interfaces and their corresponding memories. The first north bridge circuit  106  functions together with the first CPU module  102 , to execute data exchange between system processors, graphics sub-systems, memory, and peripheral component interconnect buses, and transmit video data via the first graphics card interface  124  to a graphics card (not shown in  FIG. 1 ). Similarly, the second north bridge circuit  108  functions together with the second CPU module  104 , to execute data exchange between system processors, graphics sub-systems, memory, and peripheral component interconnect buses, and transmit video data via the second graphics card interface  126  to another graphics card (not shown in  FIG. 1 ). The south bridge circuit  112  processes signal exchange between the motherboard  100  and the peripheral device  128  through the use of the peripheral interface  114 . The peripheral interface  114  can be a hard disk bus, a PCI-E bus, an expansion interface(for example an IEEE 1394 slot or a USB slot), or a network interface. Therefore, hard disks, network cards, sound cards, and external devices can exchange data with the motherboard  100  via south bridge circuit  112 . Note that in  FIG. 1  the first north bridge circuit  106  and the second north bridge circuit  108  are coupled via the selection circuit  110  to the south bridge circuit  112 . The selection circuit  110  couples the first north bridge circuit  106  to the south bridge circuit  112  when a CPU is inserted into the first CPU slot  116 , and the computer system executes corresponding functions with the first CPU module  102 , the first north bridge circuit  106 , and the south bridge circuit  112 ; or couples the second north bridge circuit  108  to the south bridge circuit  112  when a CPU is inserted into the second CPU slot  122 , and the computer system executes corresponding functions with the second CPU module  104 , the second north bridge circuit  108 , and the south bridge circuit  112 .  
         [0018]     Moreover, in  FIG. 1  the clock circuit  130  is capable of outputting clock signals to the first north bridge circuit  106 , and outputting converted clock signals corresponding to the second north bridge circuit  108  to the second north bridge circuit  108  with the clock conversion circuit  132 . Therefore, the motherboard  100 , even comprising only one clock circuit, can function together with different central processing units.  
         [0019]     Through the use of the motherboard  100  of the present invention, a user can change CPUs corresponding to the first and second CPU modules  102  and  104 , without changing the motherboard. Further, as long as a CPU module and a north bridge module are integrated into an identical CPU interface card, central processing units can be changed by plugging in cards.  
         [0020]     Please refer to  FIG. 2 , which is a block diagram of a motherboard  200  allowing selection of different central processing units of a second embodiment according to the present invention. The motherboard  200  comprises an interface circuit  234 , a first CPU module  202 , a first north bridge circuit  206 , a selection circuit  210 , a south bridge circuit  212 , a first graphics card interface  224 , a second graphics card interface  226 , a clock circuit  230 , and a peripheral device  228 . Additionally, the motherboard  200  can be combined with a CPU interface card  201  through the use of the interface circuit  234  to accommodate different central processing units. The CPU interface card  201  comprises a second CPU module  204 , a second north bridge circuit  208  and a clock conversion circuit  232 . The operation of the motherboard  200  shown in  FIG. 2  is similar to the operation of the motherboard  100  shown in  FIG. 1 . The first CPU module  202  comprises a first CPU slot  216  and a first memory slot  218 . The second CPU module  204  comprises a second CPU slot  222  and a second memory slot  220 . The first CPU slot  216  has a type different from that of the second CPU slot  222 , both of which have CPUs of different interfaces and their corresponding memories. After a CPU and a memory are inserted into the second CPU slot  222  and the memory slot  220  respectively, a user can combine the CPU interface card  201  with the interface circuit  234 . Then, the selection circuit  210  couples the south bridge circuit  212  to the interface circuit  234  and blocks signals between the south bridge circuit  212  and the first north bridge circuit  206 . Therefore, through the second CPU slot  222 , the second memory slot  220 , the second north bridge circuit  208 , and the clock conversion circuit  232 , the motherboard  200  can execute corresponding functions of the system. Note that the second north bridge circuit  208  outputs video signals via the interface circuit  234  to the second graphics card interface  226 , and converts the clock signals output by the clock circuit  230  into proper clock signals with the clock conversion circuit  232  and the interface circuit  234 .  
         [0021]     In  FIG. 2 , the motherboard  200  is pre-installed with the first CPU slot  216 , which is of a specific format. If the interface format of a CPU does not correspond to the first CPU slot  216 , a user can select a CPU interface card  201  complying with the specific format, and insert the CPU into the second CPU slot  222  through the CPU interface card  201  so as to form a complete computer system. That is to say, without changing the motherboard  200 , the user can select, depending on their specific need, a proper CPU interface card to realize the objective of using an identical motherboard to accommodate different central processing units.  
         [0022]     Please refer to  FIG. 3 , which is a block diagram of a motherboard  300  allowing selection of different central processing units of a third embodiment according to the present invention. The motherboard  300  comprises an interface circuit  334 , a south bridge circuit  312 , a graphics card interface  324 , a clock circuit  330 , and a peripheral device  328 . The motherboard  300  allows selection of different central processing units through the engagement of the interface circuit  334  and a CPU interface card. The CPU interface card  301  comprises a CPU module  302 , a north bridge circuit  306 , and a clock conversion circuit  332 . In contrast to motherboards shown in  FIG. 2  and  FIG. 3 , the motherboard  300  shown in  FIG. 3  does not comprise a pre-installed CPU module. When a user plans to install a CPU of a specific interface on the motherboard  300 , the user can select the CPU interface card  301  complying with the specific interface, and engage the interface circuit  334  to the CPU interface card  301 , which comprises the CPU the memory. Therefore, the motherboard  300  can function normally. In normal conditions, if a user plans to change a CPU with different interfaces, the user does not have to change the motherboard, but instead only the CPU interface card. Therefore, through changing of a CPU interface card, the motherboard  300  can realize selection of different central processing units.  
         [0023]     The above CPU interface card and graphics card interface are not limited to specific interface formats, as long as they can realize the object of the present invention. For example, the CPU interface card and the graphics card interface of the present invention can be of an interface format complying with a peripheral component interconnect-express (PCI-E) standard. Through the use of the motherboard of the present invention, a user can change, depending on their needs, different CPUs by plugging cards into the motherboard, so as to achieve the objective of installing a variety of CPUs on an identical motherboard. This reduces resource consumption and makes changing CPUs more convenient.  
         [0024]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method 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.