| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ATM cell format conversion circuit with a simple configuration that can always output a cell whose format is accurately converted. SOLUTION: A dual port memory 1 is provided with a memory space of 53+X bytes or over per cell so as to reserve a nonuse area of n bytes (n>=X) to which data are not written in advance so that respective data are written in a fixed address of each ATM cell at all times. In the case of reading a cell from the dual port memory 1, a read counter A7 repeats counting for a period of '53+X' sequentially from 'n-X' until 'n+52'. A read counter B6 is incremented by 1 every time the read counter A7 is circulated and repeats count-up in a range of '0'-'N'. An information insertion circuit 11 inserts information to an idle area in X bytes of a read cell.</p> |
