| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit where a protect circuit or prohibiting the reading or writing of at least a part of an internal circuit is incorporated and a protect release is enabled by the input of a fixed password. SOLUTION: The semiconductor integrated circuit is provided with a logical arithmetic circuit 2 and ROM 3 for writing a program for inspecting the circuit and the protect circuit 4 prohibiting the data reading of ROM 3 is incorporated in LSI1 which is provided with input terminals IN1 to INn, output terminals OUT1 to OUTm and an energizing control terminal CTRL. The protect circuit 4 is provided with a detecting means for detecting password data which is inputted plural times from the terminal of a previously fixed combination within the IN1 to INn terminals, a data holding means for temporarily holding detection output data of the detecting means and a judging means for detecting that detection output data becomes previously fixed array so as to execute protect release.</p> |
