| 摘要 |
PURPOSE:To check a video system efficiently with simple constitution by connecting one terminal of a digital switch for address, that of a digital switch for data, and that of a switch for control to the first power supply terminal and connecting the other ends of them to the second power supply terminal through independent resistors respectively. CONSTITUTION:Digital switches 21 and 22 for address, digital switches 23 and 24 for data, and a switch 25 for control are provided. Switches 21-24 are 4-bit switches, and each of them consists of four switches turned on or off in accordance with setting. One terminals of respective four switches of switches 21 and 22 are connected not only to terminals 71-78 for address but also to a power supply terminal 27 through independent resistors 26. One terminals of respective four switches of switches 23 and 24 are connected to not only terminals 81-88 for data but also the power supply terminal 27 through independent resistors 28. One terminal of the switch 25 is connected to not only a terminal 29 for input/output control but also the power supply terminal 27 through a resistor 31. The other terminals of switches 21-25 are connected to another power supply terminal, for example, the earth.
|
