Multiple tasks in FPGA-based programmable controller

An FPGA-based execution platform for PLC controllers with capability to run multiple control tasks is presented. The platform, called multi-CPCore, uses hardware virtual machines to execute control tasks defined in CPDev engineering environment. The tasks consist of one or more programs written in IEC 61131-3 languages, such as ST, IL or FBD. They may run with different cycles and communicate via global variables. Parallel programming mechanisms like process image and semaphores are provided to handle potential conflicts when accessing shared resources.