| 摘要 |
PURPOSE:To reduce the area occupied by a barrel shifter in a semiconductor integrated circuit by providing a shift circuit consisting of a shift register that shifts the input data by a shift clock and a latch circuit which holds the output of the shift circuit. CONSTITUTION:A barrel shifter circuit consists of an oscillator circuit 104 which starts oscillations with reception of a shift instruction signal 108, stops the oscillations with reception of a comparison coincidence signal 112, and outputs a shift clock 109, a counter circuit 105 which counts the number of pulses of the clock 109 and output a counter signal 113, a comparator circuit 106 which compares the signal 113 with a shift extent designating signal 106 and outputs the signal 112, a shift circuit 102 which shifts a barrel shifter input signal 110 by the clock 109 and outputs shift circuit output signal 114, and a latch circuit 103 which latches the output signal 114 of the circuit 102 by the signal 112 and outputs a barrel shifter output signal 111. |
