| 摘要 |
PURPOSE:To obtain an analog-to-digital converter of high accuracy, by eliminating a signal source generating noises by making a central control circuit inoperative during signal conversion. CONSTITUTION:A CPU1 accesses a memory 4 with an address line 10 and a data line 11 to execute the program of a memory 4. In the execution of AD conversion, the CPU1 sets an flip-flop via an input controlling circuit 5, the rising signal triggers a monostable multivibrator 7 and a pulse is inputted to the AD converter as a conversion starting signal 14. When the AD conversion is finished, ''1'' is outputted as a conversion end signal 15 of the AD converter, the CPU1 loses the right of control, the operation is stopped, and the address line 10 and the data line 11 can not be turned on and off. Thus, in the stage very less in the noise of the AD converter, the AD conversion is performed and when the conversion is finished, the CPU1 again starts operation. |
