Hi, I use sprintf() function, in previously message i erase 's' character from sprintf(), sorry. I use sprintf()!! PS: memory stack overflow is not present, i debug project and increase all stack memory and after if it is a stack problem why if i sprintf() a float variable as %d system work correctly?? PPS: i note in map file created from realview that the new define variable (that is U8 variable) use more than 1 byte but for example 3 byte!!Strange or normal??? It is the memory alignment!!But very strange that is the new declared variable that use more than 1 byte!! Hi, Thanks