Getting to know more about the PRU which TI is using to enable industrial communications. Shown here, is a very simplified block diagram of the PRU based Industrial Communications Subsystem. The PRU, or the Programmable Real-time unit, is a 32-bit RISC core with about four dozen machine instructions that cover arithmetic, logic, control and input/output functions. The core has a load/store architecture with single cycle instruction execution model and zero overhead for branch instructions. Some of the registers in these cores have direct connectivity to the device level pins, which allows development of customer signaling protocols. And each of the two PRUs in the AM335x device runs at 200 MHz which gives a 5 ns granularity to the I/O instructions for switching the state of the signals. As one can also see, there are UART and MII interfaces that help the PRUs with serial and Ethernet interfaces. In addition, there are single cycle multiply-accumulate peripherals, timers, time based event generators and interrupt controller peripherals in the subsystem that are designed to meet critical functionality needs in industrial automation. The PRUs have 8 KB instruction memory each and are programmed by the ARM. TI has developed PROFIBUS and EtherCAT on PRU already and additional features such as POWERLINK are in advanced stages of development. Ti is confident that the PRU based approach makes the systems much more flexible and also reduces the overall system cost and design complexity.