This course introduces programmable devices (e.g., Field Programmable Gate Arrays ' FPGAs), their usage and their characteristics. Emphasis will be put on the architectural features of the most advanced programmable devices, including the available resources for computation, storage and communication. The course will cover the notion and typical application of Systems-on-Programmable-Chips (SoPCs), together with an overview (and practical experimentation) of the design tools which are now available for optimizing the implementation of complex applications on programmable systems. Pros and cons of the programmable design paradigm will be discussed and put in perspective with the more traditional ASIC-oriented approach.