I have been struggling for a very long time trying to implement emWIN on an RA8875 with FreeRTOS. The problem (according to Segger) is caused by the touch controller being integrated into the graphics controller. Since the touch task runs separately from the Exec then each can asynchronously interrupt the other and if a memory write is done then the FIFO state can become invalid for the touch task. I have seen this repeatedly. Touches cause graphical changes (i.e. a button press) but the associated callback never happens. There are also miscellaneous hangs and other glitches. Segger suggested a MUTEX at the hardware level (which seems to solve the problem) but it is VERY slow. Has anyone been successful implementing the 8875 with an RTOS?