| 摘要 |
<p>PURPOSE:To output a ternary value as the pulse output by controlling a timer circuit which generates a timing signal, a state generating circuit which generates first, second and their states, and a switch element which drives an output terminal in accordance with the state. CONSTITUTION:A central processing unit 10 sets a time T1 of the state change and next state 01 to a timer 1 and a latch 4. Consequently, the value of a latch 5 goes to 01 at the time T1 to set the second state. At this time, an output terminal 9 outputs 5V because a first switch element 7 is made conductive and a second switch element 8 is opened. In the case of the their state, the output terminal 9 goes to the high-impedance state because first and second switch elements 7 and 8 are opened, and the potential of the output terminal 9 goes to 2.5V by voltage division of resistances 11 and 12. Consequently, the central processing unit 10 sets the time and the state to obtain the pulse output taking one of three values of 0V, 2.5V, and 5V at the arbitrary time.</p> |
