| 摘要 |
<P>PROBLEM TO BE SOLVED: To quickly perform switching of speakers without causing omission of a leading part in the guidance voice of a car navigation system 14 when an automobile approaches a guiding point in a period when an audio source 13 such as a CD player is operated to output the reproduction sound of music from the speaker, and to refrain from using the general-purpose output (GPIO) of a DSP 11. <P>SOLUTION: A speaker output switching control signal from the car navigation system 14 to the DSP 11 is sent not via a DSP control microcomputer 12 but by using the free signal line of the audio signal lines of right and left channels since a navigation voice is monaural. In other words, a monaural navigation voice and a control signal are sent to an A/D converter 24 via Lch and Rch signal lines 23l and 23r respectively. The A/D converter 24 sends the A/D converted navigation voice and control signal to the DSP 11 in a time-division manner. <P>COPYRIGHT: (C)2008,JPO&INPIT |
