Bus controller with virtual bridge

A bus controller of a computer system, via which a central processing unit communicates with a first group of components and a second group of components, the bus controller comprising:

• a bus controller main circuit electrically connected to the central processing unit;
• a virtual bridge device electrically connected to the central processing unit via said bus controller main circuit and electrically connected to said bus controller main circuit via an internal line;
• and
• a path selection unit electrically connected to said bus controller main circuit and in communication with the first group of components and the second group of components via a bus device, said path selection unit transferring a transaction to the first group of components via said bus device when a bus code carried by said transaction has a first value and transferring said transaction to the second group of components via said bus device when said bus code carried by said transaction has a second value.

A bus control method for use in a computer system, the computer system comprising a central processing unit, a bus controller main circuit, a virtual bridge device, a first group of components, and a second group of components, the bus control method comprising:

• the bus controller main circuit indicating the presence of a first-level bus that the first group of components is coupled to;
• the virtual bridge device indicating the presence of a second-level bus that the second group of components is coupled to in response to a bus configuration cycle asserted when the computer system is initialized;
• outputting a normal select signal to said first-level bus when the address data of a transaction received by the bus controller main circuit indicates a bus code of said first-level bus;
• and
• outputting a normal select signal to said second-level bus when the address data of a transaction received by the bus controller main circuit indicates a bus code of said second-level bus.