Read frequency and delay data from ROM. The frequency data is fed into the frequency generator, and the delay data is fed into the delay counter. Wait for the delay counter to decrease to 0 while the frequency generator continues to output the specified frequency.
Trigger the PC pointer to add 1 to read the next beat data. If the PC pointer is larger than the total number of beats, it is cleared to avoid reading other random data. The music chip that can produce a variety of WAV sounds plays the same principle as the sound card, burning a small piece of music data to the internal output, the data will be sent to the internal DAC according to the PC pointer for playback, if the sampling rate is 8khz, every 125 microseconds will trigger the pc pointer plus 1 to read the next data from the ROM, without decoding, usually without recording function.
Music is burned in the ROM of the chip, the specific principle should be the internal a number of tiny circuits burned to achieve the purpose of storage, the chip is through a very thin wire or contact to the circuit board, the so-called black things are just fixed seal.
The level of integration can not be judged from the shape, the integrated circuit is to the micron and nanometer level, and the image is that a resistor can be made of tens of microns to hundreds of nanometers.