The paper presents a new methodology and architecture for digital control. Control laws can be efficiently implemented with one-bit signals at both the input and output. ΔΣS modulation is used to shape either analogue or multi-bit digital signals into 1-bit format. The 1-bit signals can be applied directly to physical systems, i.e. pulse-density modulation. A modified canonic controller structure is developed, in which there are no multipliers. Some problems arising from sampling and quantisation are discussed. As an example, a practical 1-bit processing architecture for DC motor control is presented.