— The paper describes pre-integrated subsystem consisting of a configurable 8-bit microcontroller and an Internet connection solution. The latter integrates Ethernet Media Access Controller, hardware accelerator that implements TCP/IP checksums generation and analysis and the third party TCP/IP stack adapted to take advantage of the available accelerator. A reference design based on the presented subsystem is also described. It enables interaction with the object controlled by microcontroller by means of a web browser.