Hello, I am new to FreeRTOS. May I know if there is any recommended requirements of the MCU speed when using FreeRTOS? Actually I am going to port to Samsung S3C826A, 8-bit mcu of around 1~2 MIPS max. Is this chip affordable to RTOS? http://www.samsung.com/Products/Semiconductor/SystemLSI/Microcontrollers/8_bit/S3C8_KS88Series/S3C826A/S3C826A.htm

MIPS values do not really allow one processor speed to be compared directly with another  although 1-2 MIPS does sound slow. The FreeRTOS can be used in a number of different ways  with varying processing overheads.  It is unlikely that your device will be suitable for a fully preemptive solution  but then with this chip it is doubtful that the application would warrant it anyway. With a low tick frequency and cooperative scheduling the kernel can still simplify your design with very little overhead.  See the http://www.FreeRTOS.org/tutorial pages for an example. Regards.