| 摘要 |
PURPOSE:To provide the audio recording and reproducing device used in general for an information processing unit. CONSTITUTION:The device is made up of a microphone 1, an amplifier circuit 2, a delta modulation circuit 3, a start bit/stop bit insert circuit 4, a start bit/ stop bit extract circuit 5, an audio sampling clock generating circuit 6, a receiver 7, a driver 8, a recording switch 9, a reproduction switch 10, a demodulation circuit 11, an amplifier circuit 12 and a speaker 13. An audio analog signal received from the microphone 1 is converted into a digital signal by a delta modulation circuit 3 and the start bit/stop bit insert circuit 4 adds a start bit and a stop bit to the signal and the resulting signal is sent to an information processing unit 20 from an asynchronous serial interface 22 via the driver 8. The digital signal sent from the asynchronous serial interface 22 via the receiver 7 is sounded from the speaker 13 via the demodulation circuit 11. |
