Format converting system for synchronous optical network.

摘要

A format converting system includes a first converter (1; 21) which converts an input signal into N parallel signals (N is an integer). Each of the N parallel signals has a bit rate less than that of the input signal. A latch circuit (3; F11 - F14, F22 - F24) temporarily latches the N parallel signals in accordance with a clock signal and outputs a plurality of latched signals having a number larger than the N. A selector (4; 24) selectively outputs the latched signals from the latch circuit and stuff bits to be inserted into the N parallel signals in accordance with a control signal (SEL) so that N parallel output signals having the N parallel signal and the stuff bits are output from the selector. The stuff bits are used for converting a frame format of the input signal into a different frame format. A control circuit (5; 23) generates the clock signal and generates the control signal which instructs the selector to change an order of selecting the latched outputs and the stuff bits to thereby form the N parallel output signals when the number of the stuff bits to be inserted into the N parallel signals is not an integer multiple of N. A second converter (6) converts the N parallel output signals into a serial output signal having the different frame format.