Semiconductor device, microcomputer and flash memory

A microcomputer including a CPU and other circuits over one semiconductor chip,

• wherein said other circuits include a control voltage generating circuit for generating a control voltage on the basis of control data;
• a circuit using a current source transistor for generating a reference current on the basis of said control voltage;
• a current measuring transistor whose control terminal is connected to a path for supplying said control voltage to said current source transistor;
• an external measuring terminal, connected to the current terminal of said current measuring transistor, for making possible external measurement of the current flowing in said current measuring transistor;
• and a memory which holds control data and provides them to said control voltage generating circuit.

A flash memory having over one semiconductor chip an array of non-volatile memory elements whose threshold voltages are made electrically changeable, a program circuit for changing the threshold voltages of said non-volatile memory elements, and a read circuit for reading out stored information in the non-volatile memory elements,

• either said program circuit or read circuit or both have a current source MOS transistor, receiving a control voltage, for generating a reference current,
• said flash memory further including:
• a signal line for providing a control voltage to said current source MOS transistor;
• a current measuring MOS transistor whose control terminal is connected to said signal line;
• an external measuring terminal, connected to the current terminal of said current measuring MOS transistor, for making possible external measurement of the current flowing in said current measuring MOS transistor;
• a control voltage generating circuit for generating said control voltage on the basis of control data;
• and
• a memory for holding said control data and providing them to said control voltage generating circuit.