Abstract: It is an object of the present invention to solve a problem that malfunction of communication is generated by varying a frequency of a clock due to noise from outside in a case where there is no supplied signal in a circuit which performs negative feedback control so that the supplied signal and the feedback signal can maintain a fixed phase relationship between the signals. The present invention provides a configuration including a PLL circuit and an oscillator circuit, where a switch for switching an output between a signal from the PLL circuit and a signal from the oscillator circuit to the signal output portion is provided to switch from a connection to the PLL circuit to a connection to the oscillator circuit in a case where there is no received signal.

Abstract: There is disclosed a base band signal generation device and others for processing transmission data so that a reception side can restored the data without recognizing whether the data has been subjected to a processing and transmitting the data with an appropriate efficiency corresponding to the communication quality. A transmission device T judges the communication quality of a transmission path L. When the communication quality is preferable, a four-value FSK symbol is generated from the bit of the most significant part of the encoded voice data and the bit of the least significant part. When the communication quality is not preferable, a four-value FSK symbol is generated from the bit of the most significant part of the encoded voice data and a redundant bit of “0”. However, a symbol containing a redundant bit is set to the maximum value or the minimum value of the four values which the symbol value may have.

Abstract: There is provided a method of manufacturing a semiconductor device, in which removal of the resist after ion implantation becomes easy. In order to solve the above problem, the manufacturing method includes a step of removing a resist mask after a step of implanting an ion of a rare gas element. Also, another manufacturing method includes a first step of implanting an ion of an impurity element for imparting a conductivity type, a second step of implanting an ion of a rare gas element, and a third step of removing a resist mask after the first step and the second step.