| 摘要 |
In a sound volume control circuit ( 100 ) shown in FIG. 2 , an attenuation coefficient setting register ( 28 ) holds an attenuation coefficient "b". When a stop instruction STOP becomes active, an output signal "a" from a first multiplexer ( 14 ), i.e., a processing object signal "in" is multiplied by the attenuation coefficient "b" by a multiplier ( 16 ), and the output signal "c" is outputted via a second multiplexer ( 18 ), a first flip-flop ( 20 ), and a third multiplexer ( 22 ). A multiplication master counter ( 38 ) holds the number of times the processing object signal "in" acquired by one sampling is multiplied by "b". The multiplication master counter ( 38 ) counts up by using a timer ( 36 ). A multiplication temporary counter ( 32 ) loads the output signal from the multiplication master counter ( 38 ) at the assert of an acquisition timing signal "L". The process from the first multiplexer ( 14 ) to the first flip-flop ( 20 ) is repeated by the number of times of the multiplication temporary counter ( 32 ).
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