| 摘要 |
PURPOSE: A duplex structure of a processor board in an exchange is provided to be upgraded and implanted without being affected by central processing unit(CPU) kinds or upper cash structures by using a versatile memory, and by duplicating a main processor board mounted on a high speed CPU through a dynamic random access memory(DRAM) bus expansion, and by duplicating the processor board using interface signals between a slow memory bus and a system bus. CONSTITUTION: A duplex structure of a processor board in an exchange comprises memory controllers(25a,25b), memories(20a,20b), memory switches(24a,24b), duplicating control logics(23a,23b), and a backboard bus(26). The memory controllers decode addresses of a system bus according to memory banks, and record the corresponding addresses anad data. The memories store the address and the data according to the memory banks. The memory switches are composed of bidirectional buffers or one-way buffers on a memory bus. The duplicating control logics monitor buses between the memory controllers and the memories. The duplicating control logics control the memory switches and transmit the address, the data, a row address strobe(RAS) signal, a column address strobe(CAS) signal, a write enable(WE) signal to other side's board. The backboard bus transmits the address, the data, the RAS/the CAS/the WE signals to other's board, at a same speed with the memory bus.
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