This article describes the design steps for generating custom and semi‐custom integrated circuits for digital terminals. The design styles and processing techniques are discussed with special emphasis on the interaction of the device organization with the system organization. Metal‐oxide‐semiconductor technology makes possible high‐packing‐density custom integration. Logic conversion is verified by simulation, layout is performed automatically, and timing is verified by using layout information as input to the timing simulator. Gate arrays facilitate semi‐custom designing at low cost for modest scales of integration. The same design automation tools are used for both custom and semi‐custom integration. Complementary bipolar integrated circuit technology realizes high‐performance analog circuitry and can be combined with buried injector logic to integrate both analog and digital circuitry on the same chip. The combination of these technologies offers cost‐effective system integration for digital terminals.