Difference cortex-m series (graphic) today and debris study notes

The following figure switched https://www.cnblogs.com/luckytimor/p/6747026.html

 The series are Harvard architecture configuration, and the current can be used to develop keil and keil MDK can not develop R, A series of two, these two series can be developed with a DS-5. ds-5 has a free version that uses gcc compiler, there are castrated function above.