powerup & vector

the memory of a system is: RAM starts from 0x00000000 Flash starts from 0x02000000 During powerup, the PC is set to 0, but the content in 0x is random,is it possible startup correctly?

Yep… because at boot up the FLASH (with the vector table at the start) should be boot strapped to be a address 0 on CS0. Your startup code then coppies your program from flash to RAM (configured high in the address space by the startup code) and then swaps thier positions in memory so that RAM is at address 0 and FLASH is high in the memory map… at this point program should be running from the RAM at 0… BBFN Dave

have a look at this document. it gives you a good overview what really happens at startup. greets, stefan