| 摘要 |
PURPOSE:To easily execute a IC operation and to improve reliability by executing the on and off of a muting to PCM sound data with a digital circuit constitution. CONSTITUTION:PCM sound data (i) are inputted to a terminal 12 and to terminals 1, 2 and 3, a sample clock (a), a muting control signal (b) and a muting return signal (c) are respectively inputted. Selectors 131-13N are synchronized to the clock (a), the data (i) are successively selected, and outputted to an N bit selector 15 at the time of off-muting as it is and outputted to the N bit selector 15 as a ground potential at the time of on-muting. The selector 15 selects and outputs the input data of a terminal A or B by signals (b) and (c), outputs through an N bit register 16 to a terminal 18, a shifting circuit 17 executes the polarity inversion and shifting and the data is inputted to the terminal A of the selector 15. Thus, immediately after on-muting and off-muting, a level is gradually changed and the on and off of the natural muting are executed. Consequently, the IC operation is easily executed and the reliability is improved.
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