| 摘要 |
PROBLEM TO BE SOLVED: To prevent not only the abolishment and the overlap of a cell but also the possibility of the destruction of cell data by executing stepping out at the time of switching the input clock of a line part during the switching of a system, transmitting a pseudo cell before the valid cell is transmitted and establishing again synchronism. SOLUTION: In a duplexed ATM switch, the transmission side of a communication line part 1 which newly becomes a present system at the time of the system switch operation of the communication line part 1 and the reception side of the line part 8 are constituted by a high speed serial communication part 7 by straddling the communication line part 1 and the line part 8. At the time of switching the system of the communication line part 1 in the new present system, a cell synchronizing signal is stopped and is accumulated. The cell synchronizing signal is transmitted from a transmission control part 2 after cell transmission from a former present system terminates. Then, the cell synchronizing signal is transmitted faster than a regular period and the pseudo cell is transmitted to the line part 8. When the line part 8 recognizes that the cell is in a synchronism establishing state, the cell synchronizing signal is transmitted to reception side FIFO 11 and the cell is transferred. |
