AREA RESET, DATA, READONLY 
                EXPORT __Vectors 
__Vectors 
                DCD  0x2002ffff             ; top of stack 
                DCD  Reset_Handler          ; reset vector 
 
 
                AREA myCode, CODE, READONLY 
 
                THUMB 
 
CONST_VALUE_X   EQU  12 
 
 
                ENTRY 
Reset_Handler 
 
; -- Your code belongs here --------------------------------- 
 
                LDR  R0, =0 
                LDR  R1, =CONST_VALUE_X 
loop            ADD  R0, R1 
                B    loop 
             
; -- Your code ends here ------------------------------------ 
 
                END