Transfer Fault programming LPC55S69 flash

Probe: LPC-LINK2 CMSIS-DAP
PyOCD Version: 0.22.0
Target: LPC55s69

When start gdb-server, pyocd reported error. I killed process and start again, it would be OK.
I can reproduce the problem by steps: start -> Error occurred -> Restart -> OK -> Restart -> Error occurred -> Restart -> OK ...

I use other CMSIS-DAP probe, the problem occurred too.

Log:

C:\Python27\Scripts\pyocd gdb -t lpc55s69 -f 40000000 --persist
0000437:WARNING:common:STLink and CMSIS-DAPv2 probes are not supported because no libusb library was found.
0004373:INFO:board:Target type is lpc55s69
0004404:INFO:dap:DP IDR = 0x6ba02477 (v2 rev6)
0004419:INFO:ap:AP#0 IDR = 0x84770001 (AHB-AP var0 rev8)
0004451:INFO:ap:AP#1 IDR = 0x84770001 (AHB-AP var0 rev8)
0004467:INFO:ap:AP#2 IDR = 0x002a0000 (proprietary)
0004467:INFO:rom_table:AP#0 ROM table #0 @ 0xe00fe000 (designer=015 part=000)
0004483:INFO:rom_table:[0]<e00ff000:ROM class=1 designer=43b part=4c9>
0004483:INFO:rom_table:  AP#0 ROM table #1 @ 0xe00ff000 (designer=43b part=4c9)
0004483:INFO:rom_table:  [0]<e000e000:SCS-M33 class=9 designer=43b part=d21 devtype=00 archid=2a04 devid=0:0:0>
0004483:INFO:rom_table:  [1]<e0001000:DWT class=9 designer=43b part=d21 devtype=00 archid=1a02 devid=0:0:0>
0004483:INFO:rom_table:  [2]<e0002000:BPU class=9 designer=43b part=d21 devtype=00 archid=1a03 devid=0:0:0>
0004513:INFO:rom_table:  [3]<e0000000:ITM class=9 designer=43b part=d21 devtype=43 archid=1a01 devid=0:0:0>
0004529:INFO:rom_table:[1]<e0040000:TPIU-M33 class=9 designer=43b part=d21 devtype=11 archid=0000 devid=0:0:ca0>
0004529:INFO:rom_table:AP#1 ROM table #0 @ 0xe00fe000 (designer=015 part=000)
0004544:INFO:rom_table:[0]<e00ff000:ROM class=1 designer=43b part=4c9>
0004544:INFO:rom_table:  AP#1 ROM table #1 @ 0xe00ff000 (designer=43b part=4c9)
0004544:INFO:rom_table:  [0]<e000e000:SCS-M33 class=9 designer=43b part=d21 devtype=00 archid=2a04 devid=0:0:0>
0004544:INFO:rom_table:  [1]<e0001000:DWT class=9 designer=43b part=d21 devtype=00 archid=1a02 devid=0:0:0>
0004560:INFO:rom_table:  [2]<e0002000:BPU class=9 designer=43b part=d21 devtype=00 archid=1a03 devid=0:0:0>
0004560:INFO:rom_table:  [3]<e0000000:ITM class=9 designer=43b part=d21 devtype=43 archid=1a01 devid=0:0:0>
0004560:INFO:rom_table:[1]<e0040000:TPIU-M33 class=9 designer=43b part=d21 devtype=11 archid=0000 devid=0:0:ca0>
0004576:INFO:cortex_m_v8m:CPU core #0 is Cortex-M33 r0p3 (security ext present)
0004576:INFO:cortex_m:FPU present: FPv5-SP
0004608:INFO:cortex_m_v8m:CPU core #1 is Cortex-M33 r0p3
0004622:INFO:dwt:4 hardware watchpoints
0004638:INFO:fpb:8 hardware breakpoints, 1 literal comparators
0004654:INFO:dwt:4 hardware watchpoints
0004654:INFO:fpb:8 hardware breakpoints, 1 literal comparators
0004701:INFO:server:Semihost server started on port 4444
0004701:INFO:gdbserver:GDB server started on port 3333
0004717:INFO:server:Semihost server started on port 4445
0004717:INFO:gdbserver:GDB server started on port 3334
0013952:INFO:gdbserver:One client connected!
[                    ]   0%0014220:ERROR:gdbserver:Unhandled exception in handle_message: SWD/JTAG Transfer Fault @ 0x40034fe0-0x40034fe3
Traceback (most recent call last):
  File "c:\python27\lib\site-packages\pyocd\gdbserver\gdbserver.py", line 549, in handle_message
    reply = handler(msg[msgStart:])
  File "c:\python27\lib\site-packages\pyocd\gdbserver\gdbserver.py", line 768, in v_command
    return self.flash_op(data)
  File "c:\python27\lib\site-packages\pyocd\gdbserver\gdbserver.py", line 884, in flash_op
    self.flash_loader.commit()
  File "c:\python27\lib\site-packages\pyocd\flash\loader.py", line 508, in commit
    keep_unwritten=self._keep_unwritten)
  File "c:\python27\lib\site-packages\pyocd\flash\flash_builder.py", line 466, in program
    flash_operation = self._sector_erase_program_double_buffer(progress_cb)
  File "c:\python27\lib\site-packages\pyocd\flash\flash_builder.py", line 859, in _sector_erase_program_double_buffer
    self.flash.init(self.flash.Operation.ERASE)
  File "c:\python27\lib\site-packages\pyocd\flash\flash.py", line 235, in init
    self.target.reset_and_halt(Target.ResetType.SW)
  File "c:\python27\lib\site-packages\pyocd\core\coresight_target.py", line 333, in reset_and_halt
    return self.selected_core.reset_and_halt(reset_type)
  File "c:\python27\lib\site-packages\pyocd\target\builtin\target_LPC55S69JBD100.py", line 257, in reset_and_halt
    if (self.read32(base + FLASH_INT_STATUS) & 0x00000004) != 0:
  File "c:\python27\lib\site-packages\pyocd\core\memory_interface.py", line 56, in read32
    return self.read_memory(addr, 32, now)
  File "c:\python27\lib\site-packages\pyocd\coresight\cortex_m.py", line 614, in read_memory
    result = self.ap.read_memory(addr, transfer_size, now)
  File "c:\python27\lib\site-packages\pyocd\coresight\ap.py", line 564, in _read_memory
    result = read_mem_cb()
  File "c:\python27\lib\site-packages\pyocd\coresight\ap.py", line 546, in read_mem_cb
    res = result_cb()
  File "c:\python27\lib\site-packages\pyocd\coresight\dap.py", line 276, in read_ap_cb
    result = result_cb()
  File "c:\python27\lib\site-packages\pyocd\probe\cmsis_dap_probe.py", line 288, in read_ap_result_callback
    six.raise_from(self._convert_exception(error), error)
  File "c:\python27\lib\site-packages\six.py", line 737, in raise_from
    raise value
TransferFaultError: SWD/JTAG Transfer Fault @ 0x40034fe0-0x40034fe3
0014246:INFO:gdbserver:Client detached
0014247:INFO:gdbserver:Client disconnected!

Start with pyocd/target/builtin/target_LPC55S69JBD100.py and its reset_and_halt() method, then trace the read at 0x40034fe0 through the flash and GDB-server paths named in the traceback. Reproduce the start, error, restart sequence and confirm that repeated flash programming no longer produces a SWD/JTAG Transfer Fault.