| 摘要 |
<p>PURPOSE:To ensure the accurate drive of a timepiece even at a service interruption by using a control circuit which controls the working of an oscillation circuit that produces a reference clock for the timepiece and a counter circuit which works only for a due period due to detection of the service interruption. CONSTITUTION:A service interruption detecting circuit 17 detects a service interruption and transmits a signal of a low level after reception of the power from a back-up power supply. Based on said signal, a counter control circuit 13 sends a control signal to a counter circuit 14 for its start. Thus the circuit 14 counts the pulses of a timepiece reference clock for increment. While the circuit 17 transmits a signal of a high level at a non-service interruption. At the same time, the circuit 13 stops the operation of the circuit 14 and transmits a signal to reset the count value. Then the circuit 14 stops the working of an oscillation circuit 12 via an oscillation control circuit 11. Thus the working time of a CPU is decided and the normal working of a timepiece is ensured even with a short service interruption.</p> |
