TransferTimeoutError: STLink error (20): DP wait

Mbed Studio
1

Hi all,
when I start debugging in Mbed Studio ( Version 0.7.0) with Nucleo-L476RG I’ll get following error

File “c:\Users\ste\AppData\Local\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\utility\sequencer.py”, line 201, in invoke
resultSequence = call()
File “c:\Users\ste\AppData\Local\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\coresight\dap.py”, line 121, in power_up_debug
self.write_reg(DP_SELECT, 0)
File “c:\Users\ste\AppData\Local\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\coresight\dap.py”, line 117, in write_reg
self.write_dp(addr, data)
File “c:\Users\ste\AppData\Local\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\coresight\dap.py”, line 243, in write_dp
self.link.write_dp(addr, data)
File “c:\Users\ste\AppData\Local\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\probe\stlink_probe.py”, line 168, in write_dp
result = self._link.write_dap_register(STLink.DP_PORT, addr, data)
File “c:\Users\ste\AppData\Local\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\probe\stlink\stlink.py”, line 425, in write_dap_register
self._check_status(response)
File “c:\Users\ste\AppData\Local\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\probe\stlink\stlink.py”, line 292, in _check_status
raise self._ERROR_CLASSESstatus
TransferTimeoutError: STLink error (20): DP wait

Is there any solution for that?

ARM Compiler 6.11 up to date
Clangd 8.0.0 up to date
Example projects 1.2.0 up to date
GDB client 6-2017-q2-update up to date
Git 2.19.2 up to date
Mbed Library Cache 1.2.0 up to date
Python tools 0.2.0 up to date
Debug Packs 1.0.3 up to date
OS: Windows 10

Thank you
Stepan

2

Hi Stepan,

We’ve addressed this error and it’s fixed, the next release will fix this issue.

3

Hi @s_urban ,

Thank you for reporting this issue. As @sayhuthut mentioned this issue should be resolved in the newest version of Mbed Studio. You can either download Mbed Studio 0.8.0 directly from Mbed Studio | Mbed or use auto-update mechanism inside Mbed Studio 0.7.0.

Thanks,
Arek - Mbed Studio team

4

I am using 0.8.0 with the Nucleo-L476RG board. I see the same kind of error when running the “example mbed-os-example-blinky”
I’m using first time install of the Mbed Studio. Here is the stack:

[Switching to Thread 536877572]
Thread 2 “main” hit Breakpoint 1, main () at ./main.cpp:18
18 SystemReport sys_state( SLEEP_TIME * PRINT_AFTER_N_LOOPS /* Loop delay time in ms */);
0017012:WARNING:gdbserver:Exception while target was running: STLink error (20): DP wait
Traceback (most recent call last):
File “c:\ProgramData\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\gdbserver\gdbserver.py”, line 739, in resume
self.target.halt()
File “c:\ProgramData\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\coresight\cortex_m.py”, line 652, in halt
self.write_memory(CortexM.DHCSR, CortexM.DBGKEY | CortexM.C_DEBUGEN | CortexM.C_HALT)
File “c:\ProgramData\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\coresight\cortex_m.py”, line 611, in write_memory
self.ap.write_memory(addr, value, transfer_size)
File “c:\ProgramData\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\probe\stlink_probe.py”, line 222, in write_memory
self._link.write_mem32(addr, conversion.u32le_list_to_byte_list([data]), self._apsel)
File “c:\ProgramData\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\probe\stlink\stlink.py”, line 378, in write_mem32
self._write_mem(addr, data, Commands.JTAG_WRITEMEM_32BIT, self.MAXIMUM_TRANSFER_SIZE, apsel)
File “c:\ProgramData\Mbed Studio\mbed-studio-tools\python\lib\site-packages\pyocd\probe\stlink\stlink.py”, line 366, in _write_mem
raise exc
TransferFaultError: SWD/JTAG Transfer Fault @ 0xe000edf0-0xe000edf7

5

3 years and many releases later, STILL seeing this problem.

mbed studio 1.4
nucleo F401RE

what are we supposed to do, to make “DP wait” go away??

Would be nice if there were some kind of “reset board” option maybe.
but no such luck.