ARM, RISC-V контроллеры

Похоже, что там есть 2 дополнительных процессора внутри. Programmable Real-Time Unit Subsystem (PRUSS). Люминари не нужны  http://focus.ti.com/lit/wp/spry136/spry136.pdf
The PRU has access to all SoC resources including hardware peripherals, system memory, external memory, and input/output pins. This allows the PRU subsystem to leverage other system resources to implement soft peripherals. For example, a soft universal asynchronous receiver/transmitter (UART) can be implemented using a serial port for data transmit and data receive using an 8× or 16× clock for oversampling. When data is being received, the PRU could remove framing bits (start, stop, parity, etc.), extract the actual data and transfer the fi nal result to SoC memory. For the transmit case, the PRU subsystem can move data from SoC memory, add framing bits (start, stop, parity, etc.) and directly access the serial port for transmission. Also, since the PRU is programmable, custom features such as support for 9-bit characters and special baud rates can be added to the soft UART. Figure 4 on the following page shows a block diagram of a soft UART implementation using the PRU.