我用RT-Thread下载程序日志如下：

J-Link Commander will now exit on Error
J-Link Command File read successfully.
Processing script file...
J-Link>si JTAG
J-Link connection not established yet but required for command.
Connecting to J-Link via USB...O.K.
Firmware: J-Link V11 compiled Dec  4 2023 10:22:45
Hardware version: V11.00
J-Link uptime (since boot): 0d 00h 00m 29s
S/N: 601012352
License(s): RDI, FlashBP, FlashDL, JFlash, GDB
USB speed mode: High speed (480 MBit/s)
VTref=3.309V
Selecting JTAG as current target interface.
J-Link>jtagconf -1 -1
J-Link>exec device=HPM6750xVMx
Device "HPM6750XVMX" selected.
J-Link>speed auto
Selecting auto as target interface speed
J-Link>r
Target connection not established yet but required for command.
Device "HPM6750XVMX" selected.
Connecting to target via JTAG
Could not measure total IR len. TDO is constant high.
Failed to identify target. Resetting via Reset pin and trying again.
Could not measure total IR len. TDO is constant high.
Cannot connect to target.
Script processing completed.

这是什么原因呀！