| 摘要 |
PURPOSE:To reduce a space required for wiring, by constituting a shifter of first through n-th multiplexers and n+1-th through n+m-th multiplexers, and executing a prescribed left shift. CONSTITUTION:For instance,in the case of executing a left shift to '0'-7 bits, a control circuit 20 executes decoding so as to show it by the sum of shift numbers 2<0>, 2<1> and 2<2> designated by a shift number designating signal SFT 19, and controls corresponding select signals S112, S214 and S316. As a result, by multiplexers 11, 13, 15 and 17, a desired left shift is executed. Also, in the case of executing a left shift of 8 bits, the control circuit 20 sets all of the select signals S112, S214 and S316 and Se.118 to '1'. In this state, a left shift of 1, 2, 4 and 1 bits is executed by the multiplexers 11, 13, 15 and 17 and a left of total 8 bits is executed. In such a way, a physical space required for wiring can be reduced. |
