| 摘要 |
<p>PURPOSE:To obtain a microprocessor which produces no inconvenience in an evaluation test, the maintenance, etc. by securing the normal operation of the reset function in an application mode of power supply and the reset function in a voltage drop mode and attaining the control of the voltage detecting function. CONSTITUTION:A reset circuit 30 contains the 1st voltage detector 31 which uses the 1st level V1 as its reference value and the 2nd voltage detector 32 using the 2nd level V2 as its reference value. The detector 31 detects that the power supply voltage VCC exceeds the V1 and applies an output In1 to an OR gate and also a delay by a delay circuit 33. Thus an initialization signal In is obtained. In case the VCC is lowered less than the V2 owing to a short break, etc., the detector 32 works to deliver an output In2. This output is turned into the signal In in the same way via the gate OR. A control signal SC controls the transmission of the output In2. Thus the 2nd reset system can be invalidated for an appreciation test of performance, etc. This eliminate the inconvenience with an evaluation test etc.</p> |
