A barrel shifter is a digital circuit that can shift a data word by a specified number of bits in one clock cycle. It can be implemented as a sequence of multiplexers (mux.), and in such an implementation the output of one mux is connected to the input of the next mux in a way that depends on the shift distance.
For example, take a four-bit barrel shifter, with inputs A, B, C and D. The shifter can cycle the order of the bits ABCD as DABC, CDAB, or BCDA; in this case, no bits are lost. That is, it can shift all of the outputs up to three positions to the right (and thus make any cyclic combination of A, B, C and D). The barrel shifter has a variety of applications, including being a useful component in microprocessors (alongside the ALU).
Other articles related to "barrel shifter, shifter":
... A common usage of a barrel shifter is in the hardware implementation of floating-point arithmetic ... This is done by subtracting the exponents, and using the barrel shifter to shift the smaller number to the right by the difference, in one cycle ... If a simple shifter were used, shifting by n bit positions would require n clock cycles ...
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