abstract: The course studies feedback control problems in the situation when the controller and the plant exchange informations through a digital communication channel with a limited transmission rate. We will mainly focus on stabilization issues and, in particular, we will investigate the trade-off between the transmission rate available and the stability performance we can achieve. The use of the digital channel forces a sampling and a quantization of the input and output signals so that the closed loop dynamics in the interconnection between plant and controller is governed, in the case when the plant is linear, by a piecewise affine map whose asymptotics can be studied by ergodic theory and symbolic dynamics. We will show how these techniques can give important informations on the stabilization problem.