| 摘要 |
<p>PURPOSE:To attain the detection of period of a specific code with a small quantity of hardware by discriminating the period with an output of a transition circuit transiting the state of a counter in response to the state of counter and an output of a code detecting circuit in a period detecting circuit. CONSTITUTION:An input signal is inputted to a code detecting circuit 2 from an input terminal 1 and when a specific code inputted at a period TX is detected, the code detecting circuit 2 brings an output logic to logical 1 and makes the logic input to a counter 10 and the transistion circuit 11. When an output of the code detecting circuit 2 is logical 0, the counter 10 remains at the state 0 and when the output of the code detecting circuit 2 is logical 0, the counter 10 is advanced by each clock. When the code detecting circuit 2 detects a specific code again and outputs logical 1, the transition circuit 11 transits the counter 10 to the other state. A state output circuit 12 checks for the output of the transistion circuit 11, discriminates the period of the specific code and supplies an output via output terminals 13, 14,..., 15.</p> |
