CC3200不能通过CCS Uniflash连接下载程序问题的解决办法？

在一切准备就绪连接CC3200LP到电脑后，打开Uniflash，打开配置文件，修改好COM端口号，在弹出的选项Format中修改好相应参数后，但console界面提示如下
[20:04:34] Begin ServicePackProgramming operation.
[20:04:35] INFO: > Executing Operation: Connect
[20:04:35] FATAL: --- Can't connect to device !! ---
[20:04:36] FATAL: Error connecting to the device. Please check your COM port settings. Error code: 1
[20:04:36] INFO: > Executing Operation: Disconnect
[20:04:36] ERROR: Error disconnecting from the device. Error code: 0
[20:04:36] Operation ServicePackProgramming returned.
[20:04:48] Begin Format operation.
[20:04:49] INFO: > Executing Operation: Connect
[20:04:51] INFO: setting break signal
[20:04:51] INFO: --- please restart the device ---
[20:05:14] ERROR: ---reading ACK signal failed---
[20:05:14] WARNING: ---seting break signal to false failed---
[20:05:16] INFO: setting break signal
[20:05:16] INFO: --- please restart the device ---
[20:05:27] ERROR: ---reading ACK signal failed---
[20:05:28] WARNING: ---seting break signal to false failed---
[20:05:30] INFO: setting break signal
[20:05:30] INFO: --- please restart the device ---
[20:05:43] ERROR: ---reading ACK signal failed---
[20:05:43] WARNING: ---seting break signal to false failed---
[20:05:45] INFO: setting break signal
[20:05:45] INFO: --- please restart the device ---
[20:05:55] ERROR: ---reading ACK signal failed---
[20:05:55] WARNING: ---seting break signal to false failed---
[20:05:55] FATAL: --- Can't connect to device !! ---
[20:06:02] FATAL: Error connecting to the device. Please check your COM port settings. Error code: -3
[20:06:02] INFO: > Executing Operation: Disconnect
[20:06:02] Operation Format returned.
求指教。。。。