costs than that of a crystal oscillator which needs two pins and that of an external rc oscillator which needs one pin 0019 fig2 is a schematic view of a preferred embodiment of the integrated circuit with remote transmission function as shown in fig1 and only the differences from fig1 are described for simplification fosc is the input oscillation frequency and fosco is the signal of a waveform i e the output carrier produced by the frequency prescaler 21 hdout is the signal of a waveform produced by the hardware modulator 24 the multiplexer 25 includes two p type field effect transistors fet 252 and 254 two n type field effect transistors 253 and 255 and an inverter 251 the carrier hdout produced by the hardware modulator 13 is inputted to the sources of the p type field effect transistors 252 and 254 and n type field effect transistors 253 and 255 and the drains of the p type field effect transistors 252 and 254 and n type field effect transistors 253 and 255 are connected to the output buffer 26 the gates of the p type field effect transistor 252 and n type field effect transistor 255 are connected to the output of the inverter 251 and the gates of the p type field effect transistor 254 and n type field effect transistor 253 are connected to the input terminal of.