Delay of "SVC"

Hello: 

 There is MCU based on CORTEX-R5. When I execute "SVC #0xFF" to request SVC exception, CPU dose not jump to vector table immediately and executes some codes sequently. If I put a breakpoint on "SVC", CPU will jump to vector table immediately. Use "ISB" behind "SVC" is not useful.

  Is there a delay after execute "SVC"? How to solve that? 

Thanks.