| Barrel Shifter |
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| CATEGORIES ABOUT BARREL SHIFTER | |
| digital circuits | |
| computer arithmetic | |
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Take for example a four-bit barrel shifter, with inputs A, B, C and D. The shifter can cyclically alter the order of the outputs. That is, it can 'shift' all of the outputs up to three units to the right (and thus make any cyclic combination of A, B, C and D). Barrel shifters have a variety of applications, including being a vital component in Micro-processor s (alongside the ALU ). The barrel shifter is vital in floating point arithmetic hardware operations. For a floating point add or subtract operation, the mantissas of the numbers must be aligned, which requires shifting one of them to match the other. If a conventional shifter is used, shifting a 32-bit number, in a worst-case scenario, would require 32 clock cyles, creating a significant overhead. EXTERNAL LINKS
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