| 摘要 |
PURPOSE:To improve the processing speed of the titled circuit by detecting the boundary of an address of a maximum capacity of a data transferred at once from a CPU to a memory so as to count up an address boundary space. CONSTITUTION:A CPU is connected to a memory having a memory area larger than the address width of the CPU via a system bus and a memory controller makes all addresses of the memory addressable. Prior to the data transfer, the CPU outputs an address to an I/O latch and uses an output of a NAND2 to clear a F/F2 simultaneously. Then the data is transferred and subject to the processing of NAND1 with the output of the CPU to change the state of the outputs Q, inverse of Q of the F/F2, holds it during a prescribed output of the CPU, the boundary of the address transferred to the memory is detected and the address boundary space is counted up by a full adder to improve the processing speed.
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