TDA7313 and TDA7315 are digital controlled audio processors that can be used in applications where digital control of audio is needed. TDA7313 and TDA7315 are are pretty same just TDA7313 is more complex by hawing 3 stereo input channels and two outputs (front and rare). Both chips have volume control (step=1.25dB), tone (bass and treble) balance, independent faders for each output processors. Also there are loudness functionality. TDA7313 and TDA7315 have low distortion, low noise, that makes them ideal for quality audio applications for car audio and Hi-FI systems.
Both chips can be controlled by MCU via I2C(TWI) protocol. This makes easy to interface microcontrollers with additional features like LCD, buttons. Or simply control directly from PC using RS232 or other interface. Both chips can be found in DIP or SO packages. Here are Eagle libraries of both digital audio processors that I have made.
tda7315.zip(2kB) tda7313.zip(2kB)
I have intent to make control board with TDA7315 with LCD and button control using Atmega8 microcontroller.
very useful site for beginners