Digital signal processing (DSP) is currently the most widely used means of resolving problems in the field of information technology, automation, measurement technology, science and other fields. Digital systems have many advantages over analog systems. DSP system can be easily modified through a modification of the software. In the case of an analog system modification is necessary to change the design of the whole circuit. DSP system can be easily and accurately reproduced. The analog system is loaded with components tolerance and dependence on temperature or supply voltage. Features DSP system does not change with time, because the properties of digital components do not change with time. In our text we will focus on theoretical and practical aspects of implementation of digital filters using ATxmega16 microcontroller from Atmel.