| 摘要 |
PURPOSE:To exercise level control easily by means of an analog level meter only and to deliver an analog output by incorporating a digital pattern generator for level control in a CODEC. CONSTITUTION:The clocks 9 and synchronizing input pulses 10 are counted by counters 13 and 14 of a PCM coding device respectively, and the count values of the counters 13 and 14 are supplied as the address of a memory 12. With this address, a fixed pattern is produced from the memory 12. Then the output of the memory 12 is applied to a logical circuit of a selector 11, and at the same time a digital nput 8 and a control input 15 are supplied to the selector 11. The selector 11 changes the input 8 over the fixed pattern and adds the fixed pattern to a CODEC6 together with the input 9 and the pulse 10. Then the level control is carried out by means of an analog level meter only, and an analog signal 7 is delivered just with switching of the control input. |
