Has tool for find out the code i will write and put on Cortex M? Can somebody find out the code will I write and I put on Cortex M and how to protect from this?
Many vendors have implemented some sort of "protection" for the flash memory on their chips, to prevent it from being read by a programmer (and likewise, to disable jtag/swd.) But these are usually outside the scope of the ARM "Cortex M" definition and are vendor-specific.