SIGNAL GENERATING CIRCUIT

PURPOSE:To increase the number of combinations of codes, and also to increase the number of addresses without exerting influence on the whole system when the address has been increased, by adding a scrambling circuit constituting of a logical circuit, and an exclusive logical circuit. CONSTITUTION:To a signal generating circuit for generating an address signal of loop constitution of a data transmission system, or a loop constitution signal, etc., FFs 132-13m of (m) steps (m) is >=3 integer are cascade-connected, and a shift register 13 for constituting a scrambler, and a step number deciding circuit 11 for decreasing the effective number of steps of the register 13 are provided on said circuit. Also, a feedback step number deciding circuit 14 for inputting control signals 81-8m-1 from the control part is provided, and also a gate group 12 for inputting control signals 72-7m-1 is provided. Subsequently, an output of the register 13 is provided to an exclusive OR circuit group 16 from the circuit 11, exclusive OR of an output of an intermediate step of the register 13, and an output of the circuit 14 designated by the signals 81-8m-1 is taken, an input signal of the register 13 is decided by logic of an output of the circuit 14 and its input signal, and the combination of codes is increased.