| 摘要 |
PURPOSE:To execute various shift operations in a prescribed processing time independently of the shift amount by selecting and generating data to be buried to an idle bit from the result of operation in response to the shift operation mode and direction by a selector group. CONSTITUTION:Data except the most significant bit 2 of n-bit data 1 to be shifted, or a bit 2 of the data 1, or an immediate 5 is selected by an (n-1)-bit selector group 3. Data except the least significant bit of the data 1 or the immediate 5 is selected and outputted by an (n-1)-bit selector group 4. Data of continuous (2n-2)-bit being an output of the selector group 4 is inputted to a level shifter 6 in the least significant bit of the output of the selector group 3. The shifter 6 selects and outputs n-bit data according to a control signal 22 from a decoder 21 inputting the shift amount command signal 18 and the shift direction signal 8, and the most significant bit of the shifter 6 or the bit 2 of the data 1 is selected and outputted by a selector 7. A control signal to the selectors 3,4,7 is outputted from the control circuit 12 inputting the signal 8 and the shift mode command signals 9-11. |
