UC3B256，JTAG出错！

violaine1118

正在用UC3B256的板子开发RS485的过程当中，一开始可以将程序烧进单片机，正常运行，但是突然就不能再烧写程序了。。。

出现如下错误
Connected to JTAGICE mkII version 6.6, 6.6 at USB:0700000024B3.
No device detected. Tried both JTAG and aWire.
Failed to initialize AVR32 aWire mode.
setParameter:
The command was not understood by the JTAGICE mkII unit.
Failed to initialize AVR32 JTAG mode.
Got unknown JTAG ID: 0x0000.

如果是读取单片机信息，有如下错误
Connected to JTAGICE mkII version 6.6, 6.6 at USB:0700000024B3.
The chip is protected. Perform a chiperase command to enable programming.

于是我进行chiperase， 又会有如下错误

Connected to JTAGICE mkII version 6.6, 6.6 at USB:0700000024B3.

JTAG chip erase failed. IR=0x15.

真是奇怪了，之前一直都挺好的。。。突然就不行了，难道是单片机坏掉了？
求解答，哪位大侠知道原因啊。。。非常感谢！！！

Gorgon_Meducer

上电以后检查核心电压，可能是BOD设置错了？
建议发送邮件到avr32.cn@atmel.com，很快会有答复。