ARM and Assembly

I need info about symbols for " CODE  " , " DATA " and the syntax to
make a pure ASM code for ARM without configure ports , timers , stack
...  . I tried this but give only error , with this sample what the
correct syntax .


      ldr R7,=CONST

LOC_0:
      BL   callsub
      ldr  r1,r0
      cmp  r1,#1000
      beq  loc_0


callSUB       <------------------  don't recogzine this sub function

       mov r0,#1000
       mov pc,lr


const DCD 0x03030303  <----   error on this data