| 摘要 |
8-bit absolute value calculation method and circuit. The circuit has first to eighth subtracters for subtracting a subtrahend from a minuend in the unit of bit, first to fourth signal selectors for selecting differences and borrows from the second, fourth, sixth and eighth subtracters, respectively, according to borrows from the first, third, fifth and seventh subtracters, fifth and sixth signal selectors for selecting differences and borrows from the second and fourth signal selectors, respectively, and differences from the third and seventh subtracters, respectively, according to borrows from the first and third signal selectors, a seventh signal selector for selecting differences and borrows from the sixth signal selector and differences from the fifth subtracter according to borrows from the fifth signal selector, an eighth signal selector for selecting differences from the first subtracter, differences from the first signal selector, differences from the fifth signal selector and differences and borrows from the seventh signal selector according to a higher-order one of the borrows from the seventh signal selector, and a signal calculator for calculating a difference from the eighth signal selector according to a most significant bit thereof to output an absolute value.
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