| 摘要 |
The switching unit receives PCM groups as wellas switches in the same group a predetermined number of bits allocated in the time channels of the PCM input groups to the time channels of the PCM output groups. X switching cells (CC1,..., CCX), where X represents the maximum possible of switching operations performed in the same mesh, are suitable to receive the input groups, and to select the group and channel intersted by a time switching operation of the byte allocated in the selected time channel. A first multiplexer (MX1) receives the outputs of the X switching cells (CC) and transfers to the output the byte keyed by the switching cell corresponding to the digital word applied to it's control input. A control (CN), forwards to each switching cell (CC) a first digital word (output a) expressing the PCM channel and group interested by a switching operation as well as a second digital word (output b) expressing the time channel intersted by a scanning operation at the time which has been considered. It forwards a third digital word (output c) to the control input of the first multiplexer. |
