Abstract: A data transfer system including a data transmission unit and a data reception unit, the data transmission unit including an arithmetic unit which, when accepting an interruption during data transfer, suspends processing in execution and immediately switches to a mode for executing the interruption processing, and the data reception unit including a received data accepting unit for temporarily accumulating received data, a data storage unit for receiving and storing received data accumulated at the received data accepting unit after the data transfer processing is completed, and a transfer control unit for inhibiting processing of shifting received data accumulated at the received data accepting unit to the data storage unit when detecting suspension of the data transfer processing due to generation of an interruption at the data transmission unit.

Abstract: A current controlled oscillator is provided for reducing oscillation frequency variation because of temperature dependence of the current amplification efficiency of transistors, comprising a differential amplifier having a pair of transistors, a capacitor collected between collectors of the pair of transistors, and a positive feedback circuit for turning each of the pair of transistors to ON and OFF alternately and complementarily. A temperature compensation circuit is provided for supplying one of the collectors of the pair of transistors with a compensation current proportional to a base current of one of the pair of transistors at status ON together with a constant current.

Abstract: An automatic regulating circuit gradually regulates an output voltage to a reference value in synchronism with a clock signal, and has a binary search controller changing the value of a control signal across a final value corresponding to said reference value until a convergence at the final value; the control signal is supplied to a level shifting system so as to converge the output voltage at the reference value, and the automatic regulating circuit quickly completes the voltage regulation.

Abstract: A clamping circuit has a differential amplifier having a pair of transistors for comparing a voltage of an output node and a constant clamp voltage. The pair of transistors has a common emitter node supplied with a constant current from a first current source. An output of the differential amplifier is supplied to a base of a transistor for charging the output node. The output node is discharged constantly by a second current source. The constant current from the first current source is twice as large as the constant current from the second current source. The first and second current sources are controlled and activated to generate the first and second currents according to a current control signal. The clamping circuit also has a current control circuit for setting a value of each of the first and the second constant currents. The current control circuit is controlled by a clamp control signal and selectively activates the circuit and second current sources.