| 摘要 |
Each unit of a daisy chain of separate and independent multiplexing units (10, 12,14) is arranged to accept a group of local audio inputs (Audio 1 - Audio 8) and an additional input (18, 20, 22) from a prior unit in the chain to time division multiplex the additional input with the local units. Each unit provides a single serial bit stream output (20, 22, 24) which comprises the additional input to the next identical multiplexer unit in the chain. The next multiplexer unit time division multiplexes all of its inputs to provide a single output which includes a serial presentation of its own local inputs and the local inputs of the preceding multiplexer unit of the chain. This single serial output of the next multiplexer then forms the additional input of a still further multiplexer unit of the chain, which itself may have its own local inputs. The third multiplexer unit provides a single output that is a serial presentation of the local inputs of all three multiplexers. Additional multiplexer units can be added to the chain as may be necessary or desirable to accommodate reconfiguration of systems with which the multiplexers are used. For serial presentation of the local inputs of the several multiplexers units, system timing (84) provides a time frame, common to all units, that is subdivided into a number of subframes (subframes 1,2,3), which number is equal to the maximum number of multiplexer units that is expected to be employed in the chain. Each individual multiplexer unit of the chain is assigned a specific one of the subframes which uniquely contains data of its local inputs. For multiplexer units at the beginning of the chain only those subframes at the beginning of a frame may have data, whereas other subframes contain no data. For a final multiplexer in the chain, where the number of multiplexer units is equal to the number of subframes, all subframes contain data, with the data of each subframe being unique to the local inputs of the single individual multiplexer unit corresponding to the particular subframe. <IMAGE> |
