| 摘要 |
PURPOSE:To reduce the number of terminals by providing terminals which serve both as input and output permitting changing over with a switch. CONSTITUTION:When a reset switch 5 is OFF, the control terminal of the transmission gate TG of a changeover circuit 3 is pulled down to connect input terminal 4 to an exclusive-OR circuit G1. The test signal, etc. from the terminal 4 are then applied to a frequency dividing circuit 6. When the switch 5 is turned ON, the gate TG is pulled up to connect the terminal 4 to a frequency divider 2. The terminal then becomes output terminal, thus one terminal is selectively changed over and used for both input and output. Hence, the number of terminals of an IC circuit for watch may be reduced. |
