dwt简介Data Watchpoint and Trace (DWT)
Data Watchpoint and Trace (DWT) for real-time variable monitoring and PC-sampling, which can in turn be used to periodically output the PC or various CPU-internal counters, which can be used to obtain profiling information from the target.

使用J-LinkV8
IAR版本6.6
调试串口波特率：115200

串口输出：
//在没有仿真的情况下进入Debug中断
External Pin Reset

K70-256pin      Silicon rev 1.0
Flash parameter version 0.0.8.0
Flash version ID 1.0.18.0

DWT watchpoint demo!!

Hit any key to start

set dwt watchpoint
//此时程序发生仿真中断，LED_D31灯亮起

****default_isr entered on vector 12*****

comparator match

//进行仿真时
Software Reset

K70-256pin      Silicon rev 1.0
Flash parameter version 0.0.8.0
Flash version ID 1.0.18.0

DWT watchpoint demo!!

Hit any key to start

set dwt watchpoint
//此时程序仿真发生中断，LED_D31灯亮起，按IAR下按F5继续运行程序
comparator match

简单的说就是设置好触发源，在希望输出调试信息的地方操作触发源触发该中断。