摘要 |
A complete voice record and playback system capable of being powered by a single 1.8 VDC battery is operated in either stand-alone or CPU modes. In the stand-alone mode, two-button operation controls record, play, and memory erase functions. In CPU mode, commands may be provided through a serial interface which directly control record, playback, specialized memory management functions, and power amplifier gain settings. Through a serial interface, the system may be set up to directly write to external memory, using an analog signal generated by a microphone or other analog input device, or may instead be set up so that digital data provided by an external CPU and converted to analog using the on-chip D/A converter may be output by the speaker in real-time. |