| 摘要 |
A frame alignment method and apparatus are disclosed for aligning the t.d.m. frames of tributaries, each including channel bytes synchronously multiplexed with a frame synchronizing byte, which are byte-interleaved to form overall t.d.m. frames identified by a frame synchronizing word, the tributaries having arbitrary frame phases with respect to one another. A channel counter is reset in response to the frame synchronizing word, and for each tributary in response to the frame synchronizing byte the count of the channel counter is used to determine an offset value which is stored in a memory. Each byte of each tributary is stored in a RAM at an address determined by substracting the respective tributary offset from the current count of the channel counter, whereby the tributaries are stored in the RAM in a frame-aligned manner. Reading of the tributary bytes can be effected sequentially or via a connection memory providing a time switching function.
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