| 摘要 |
There is disclosed an apparatus for enabling one to increase the bandwidth of a multi-channel digital switching system. Essentially, the system allows one to set up multi-channel link paths to obtain a total band width of N times the bandwidth of a typical switching path in a digital switching network. To do this, a common frame counter is located in the unused bit positions of the sample in each of the paths, forming a wideband channel. At the receive end, the apparatus de-skews the received samples to properly reassembly the output. This operation is provided by utilizing one content addressable memory and an associated random access memory (CAM/RAM) (C/R) for each channel to be joined. The width of each C/R is twelve bits, eight for data, the read-out section and four for frame counter, which is the associative section. The length of each C/R is a function of the maximum skew to be counted. A four bit output frame counter provides the associative addresses for the C/R which, when given an associative address corresponding to a frame number, will respond with an eight bit data word for that frame or with an Empty signal, meaning that no word exists for that frame number. At initialization the frame counter presets to one and all C/Rs are interrogated to see if they contain frame one information. If they do not, then the output frame counter is indexed and all C/Rs are re-interrogated at a fast rate until they all indicate not Empty. At this point, the outputs of each C/R for the frame count indicated are assembled into an output word. Thus as long as all the C/Rs indicate not Empty, frame integrity is insured, and hence the distributed control switching system can provide wideband operation via multi-channel linked paths while insuring frame integrity. |
