| 摘要 |
<p>PURPOSE:To decrease memory capacity and to shorten time for developping a program by replacing a soft means, which is fixed for recognizing the cycle of an input signal, with the hard means of the microcomputer. CONSTITUTION:When an edge detection circuit 1 detects the rising edge of the external input signal of the microcomputer, an internal clock 7 is counted by a detection signal 4. However, time for the rising edge of the next input signal is predicted from an internal bus 8 by a program instruction in advance, a value smaller than a minimum time data value is set to a first counter 2, and a value larger than a maximum time data value is set to a second counter 3 respectively. Then, before detecting the next rising edge, the operation of the first counter 2 is completed, and a count end signal 9 is generated. Afterwards, the gate of an interruption signal control circuit 6 is opened, an interruption signal 11 is outputted and it is recognized that the state is within the range of the time data value predicted in advance. Thus, the cycle of the input signal can be recognized.</p> |
