This paper describes the design and implementation of functionally distributed control architecture for real-time control of robot systems. Robot systems must control several functions in parallel for decision, action, and recognition. In order to fulfill this requirement, we propose the architecture based on parallel/distributed control. The robot system based on this architecture is designed as a parallel/distributed computer, in which each module has different I/O peripherals and executes functionally distributed and coarse-grained tasks in real-time, cooperating with each other. We also evaluate the efficiency of the proposed architecture through the experience in implementing a prototype robot.