| 摘要 |
PURPOSE:To set an optical number of modes regardless of the number of input terminals and in accordance with the constitution of a counter by controlling an input means which increases the counter value and setting a desired test mode with the state transition of a counter. CONSTITUTION:When a test mode 2 is set, a signal of an L level is impressed to a reset input terminal 2 to reset a device. The level of an input signal 1 is changed as L H L L, and the value of a counter 3 are increased twice. Thus the test mode signal 2 of a decoding circuit 4 is set at an H level. When a normal action is reset, a signal of an H level is impressed to the termi nal 2. Then the counter 3 is reset and the normal mode signal of the circuit 4 is set at an H level. As a result, the mode switch control is facilitated and no input terminal is required to prescribe the test mode. As a result, an option al number of test modes are set in accordance with the constitution of the counter 3 regardless of the number of input terminals. |
