Loop:                   ;cycles
   movx   @a,dptr       ;2
   inc    dptr          ;2
Wait_ti:
   jnb    ti,Wait_ti    ;2
   clr    ti            ;1
   mov    sbuf,a        ;1
   djnz   r3,Loop       ;2
   djnz   r2,Loop       ;      2, but mostly irrelevant
                      ;-----
                      ;  10