| 摘要 |
<p>The relay switches frames between input channels (VEi) and output channel (VSi) by multiplexing the channels at frame-cell level. A frame is divided into cells having a constant bit number, whereas the frames have a variable length. The switch-relay retransmits only those frames which have been entirely written into buffer memory. A context memory (MCTX) retains the address of the first cell at the start of the writing of a frame into buffer memory, and stores the destination output channel address of the frame, until the frame is entirely written. A monitoring circuit (CEFS) checks that the writing of the frame causes no "overflow" in the buffer memory, by updating the numbers of cells waiting to be read and respectively associated with the output channels. If there is no overflow, the address of the first cell of the frame is written to one of the address queues (FS0 to FSI-1) as a function of the address of the destination channel. The frame is subsequently read by incrementation of the address of the first cell, until the end of the frame is detected.
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