Patent ID: 7928777
Filing Date: 2011-04-19
Classification: G06F

Abstract:
1. A semiconductor device comprising: a step-down circuit group including a plurality of step-down circuits that step down an external power supply voltage to a predetermined voltage; a plurality of functional circuits that require a reset operation upon power-on; and a power-on reset circuit that outputs a reset command to the plurality of functional circuits, when an internal power supply voltage supplied from the step-down circuit group exceeds a voltage level necessary for an initialization operation, wherein the plurality of step-down circuits of the step-down circuit group are classified into a startup operating step-down circuit group that performs a step-down operation from power-on to supply the internal power supply voltage, and a startup non-operating step-down circuit group that stops operation upon power-on to interrupt supply of the internal power supply voltage, and the startup non-operating step-down circuit group includes the plurality of step-down circuits sequentially selected from one having a shortest wiring distance from the power-on reset circuit.