"Could not stop ARM devices,please check JTAG cables" will frequently occues, if you use keil Vision IDE, the follows are some common reasons that cause the error. 1. JTAG cables issue 2. JTAG speed is too high, for some older device suggest choose 100khz 3. IAP is not functional, if you MCU encters abort mode, after power on, the IAP is not functional absoutly, no matter whether caused by software or hardware