| 摘要 |
PURPOSE:To reduce the number of constituting elements and prevent the increment of the chip size, by adding the test function where the output of a comparator is outputted to an external terminal and contents of a successively comparing register can be increased. CONSTITUTION:A switch circuit 9 is provided between the output of a comparator 31 and the input of a control circuit 13. In the test mode, a switch MISFET 11 is turned off and a switch MISFET10 is turned on in the switch circuit 9, and the output of the comparator 31 is taken into a testing means through a terminal P31. In the normal A/D converting operation, switches MISFETs 11 and 10 are turned on and off respectively, and the output of the comparator is supplied to the control circuit 13 as it is, and a digital signal corresponding to the analog signal supplied to a terminal P11 is set to a register 8. |
