Electronic device for computer
First Claim
1. A computer comprising:
- a mother board having a first CPU mounted thereon;
an expansion board having a second CPU mounted thereon connected to said mother board, said expansion board being connected to said mother board such that an address and data bus of said second CPU is connected to an address and data bus of said first CPU, said expansion board further including;
an expansion memory bus which is connected to a terminal for memory control of said second CPU and which has a bus width wider than a bus width of said address bus of said first CPU;
a memory means allocated in an expanded memory address area expanded by said expansion memory bus; and
a memory control means connected to said expansion memory bus and to a control signal line for memory control, said memory control means causing said second CPU to access said memory means when a memory address specified by said second CPU is in said expanded memory address area, wherein said second CPU controls said computer.
1 Assignment
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Accused Products
Abstract
The electronic computer device according to the present invention comprises an alternative CPU 22 which operates in place of a low-speed CPU on the mother board when it is connected to such as a connector on the mother board of a computer. The electronic computer device 20 is provided with an address bus on its PCB 24, of which bus width is larger than that of the address bus on the mother board 50, and the dual in-line memory modules inserted in the expansion slots 40 connected to the such address bus provides an address space larger than 16 Mbytes. The alternative CPU 22 which can utilize this large address space can perform processing beyond the limitation of the bus width of the address bus on the side of the mother board 50. The DMA transfer to an address area which is not supported by the DMA controller on the side of the mother board 50 can be realized simply by performing the DMA transfer once to the address area of lower significance.
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Citations
15 Claims
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1. A computer comprising:
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a mother board having a first CPU mounted thereon; an expansion board having a second CPU mounted thereon connected to said mother board, said expansion board being connected to said mother board such that an address and data bus of said second CPU is connected to an address and data bus of said first CPU, said expansion board further including; an expansion memory bus which is connected to a terminal for memory control of said second CPU and which has a bus width wider than a bus width of said address bus of said first CPU; a memory means allocated in an expanded memory address area expanded by said expansion memory bus; and a memory control means connected to said expansion memory bus and to a control signal line for memory control, said memory control means causing said second CPU to access said memory means when a memory address specified by said second CPU is in said expanded memory address area, wherein said second CPU controls said computer. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An expansion circuit board for upgrading an original CPU which is mounted on a mother board of a personal computer and which is connected to an address bus having a first bus width, comprising:
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an expansion CPU; a connector for connecting said expansion board to said computer, said connector connecting said address bus of said original CPU to said expansion CPU; at least one slot for receiving an expansion memory; an expansion memory bus connected to a terminal for memory control of said expansion CPU and said at least one slot for receiving said expansion memory, said expansion memory bus including an address bus having a second bus width wider than said first bus width; and a memory control unit connected to said expansion memory bus and to a control signal line for memory control, said memory control unit causing said CPU to access said expansion memory when a memory address specified by said CPU is in said expansion memory. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
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Specification