| 摘要 |
PROBLEM TO BE SOLVED: To improve the reliability of the starting position detection of frames by a presio-chronous system at the time of transmitting ATM cells by providing a first detection circuit which detects the starting position of the frame of frame synchronizing signals, a second detection circuit which detects a prescribed frame position, and an evaluating circuit. SOLUTION: A transmitter is provided with a first detection circuit 1 which sets a first detect signal D1 to a first state based on the detection of a first bit sequence at the starting position of a signal frame, a second detection circuit 2 which sets a second detect signal D2 to the first state based on the detection of a second bit sequence at a prescribed frame position of signals, and an evaluation circuit 3. The evaluation circuit 3 is provided with a frame counter 10 which resets the first detect signal D1 to the initial value when at least the starting position of the frame is detected after the first state and a coupling circuit 15 which outputs a frame status signal R. |
