as we know supervisor mode is priviliged and user is not. at reset time in debugging mode, i read the cpsr it is 0x1d3 means in supervisor mode, so i can change CPSR so i changed it to 0x1d0 which is user mode, since user mode is unpriviliged so i must not able to modify CPSR, but when i again write it to 0x1d3, i updates. why is it so?