芯片是F415，设置断点， 就一个十几行的小程序。
用FET硬件仿真调试程序，在单步执行一条if语句时，执行不下去，出现以下提示.
Fri May 23 14:45:34 2014: Failed to set hardware breakpoint. All available resources are already in use.
Fri May 23 14:45:34 2014: Virtual breakpoints can be enabled in Options dialog under Debugger->FET Debugger->Breakpoints
Fri May 23 14:45:34 2014: Performance warning: Lack of breakpoints forces single-stepping.
请问这是为什么呢？看了说明书，看不明白，急求怎么解决？！！
