Data transmission circuit

摘要

A data transmission circuit is disclosed which is arranged so that when transmitting data and control signals of a terminal equipment accommodated in a transmission line of 64 Kbps channels through use of a multi-frame arrangement, the data is assigned to a required number of bits in a predetermined number of frames in the multi-frame or adjacent ones of the predetermined number of bits and at least one synchronization flag bit and various control signals are assigned to the remaining bits but a request to send signal and the synchronization being assigned to one of the remaining bits according to the logic OR of their succeeding sampled values, whereby data of different transmission speeds can be transmitted by the same circuit.