Semiconductor memory

A semiconductor memory, comprising:

• a first internal circuit operated by an external source;
• a second internal circuit operated by an internal voltage-down-converter which outputs an internal voltage lower than the voltage of the external source;
• wherein,
• the voltage-down-converter has a reference-voltage-source circuit generating a reference voltage and a voltage-down-circuit generating the internal voltage from the external source by reference to the reference voltage, the internal voltage-down-converter outputting the same voltage as the reference voltage and supplying that voltage to the second internal circuit as the internal voltage;
• wherein,
• the reference-voltage-source-circuit comprises a standard-voltage-generation-circuit generating a standard voltage equal to a standard internal source voltage, a gate circuit outputting the standard voltage as the reference voltage to an output terminal when control signals from outside are of a first logic level, a dividing circuit outputting step voltages of a plurality of levels to the output terminal by dividing voltages from the external source, and a step-voltage-output-circuit which selects any one of the step voltages output from the dividing circuit according to data supplied to external terminals to output the selected voltage as the reference voltage when the control signals from outside are of a second logic level.