| 摘要 |
PURPOSE: An I/O(Input/Output) port for data access is provided to enhance the code efficiency by improving an execution speed of a software as lessening the load of the software. CONSTITUTION: The I/O port(40) comprises an 8-bit data port(41) as same as the conventional, and a bit control register(42) for controlling a bit by connecting to the port(41). The I/O port includes total 13 bits. The lower 8 bits are allotted to a data value, and the upper 5 bits are allotted to the value for controlling the bit. The upper 5 bits are a logic part to improve the hardware performance of the I/O port(40). The upper 3 bits of the 5 bits decide the bits for controlling the port(41) and the lower 2 bits decide the value writing to the bits for controlling the port(41).
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