| 摘要 |
PURPOSE:To assign automatically an initial value different from each device at power-on by using the different time constant of a power-on reset circuit at every device. CONSTITUTION:The power-on reset circuit 5 is a circuit having a time constant and when a prescribed time elapses after the application of power, a reset pulse going to H from L level is outputted to the input terminal CK of a latch circuit 4 through a reset pulse signal line 12. The latch circuit 4 latches a PN series signal generating circuit 2 at the leading of a reset pulse to obtain the initial value of the PN series signal. The time constant of a power-on reset circuit 5 is increased and an element having a large variation is used as an element deciding the time constant and the variation of the reset pulse width is designed to be sufficiently larger than the period of the PN series signal generating circuit 2, then the initial value of the different PN series signal at every device is automatically generated. |
