Main features of digital systems based on high speed integrated circuits will be discussed and design guidelines will be illustrated through examples and laboratory experiences. Main topics: Digital transmission lines. Switching noise. Cross-talk. "Lay-out" problems, Printed Circuit Board design. Dedicated devices and subsystems (DSP, FIR, FFT, DDS, PLL). Systems for wideband signals acquisition and synthesis. Timing of high-speed digital circuits, metastability, clock distribution. Design of programmable digital circuits: DSP and FPGA. VHDL programming. Laboratory examples.