Hi Pascal,
I have installed KDS 3.0.0
I created a new kinetis project.
I tried to flash one of my non working boards, I get the following:


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
850,007 2-gdb-version
850,012 ~"GNU gdb (GNU Tools for ARM Embedded Processors) 7.6.0.20140731-cvs\n"
850,012 ~"Copyright (C) 2013 Free Software Foundation, Inc.\n"
850,013 ~"License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\nThis is fre\
e software: you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitt\
ed by law. Type \"show copying\"\nand \"show warranty\" for details.\n"
850,013 ~"This GDB was configured as \"--host=i686-w64-mingw32 --target=arm-none-eabi\".\nFor bug re\
porting instructions, please see:\n"
850,013 ~"<http://www.gnu.org/software/gdb/bugs/>.\n"
850,013 2^done
850,013 (gdb)
850,014 3-environment-cd C:/Users/Mario/workspace.kds/prueba
850,022 3^done
850,022 (gdb)
850,023 4-gdb-set breakpoint pending on
850,032 4^done
850,032 (gdb)
850,032 5-enable-pretty-printing
850,042 5^done
850,042 (gdb)
850,043 6-gdb-set python print-stack none
850,052 6^done
850,052 (gdb)
850,053 7-gdb-set print object on
850,062 7^done
850,062 (gdb)
850,063 8-gdb-set print sevenbit-strings on
850,072 8^done
850,072 (gdb)
850,073 9-gdb-set charset ISO-8859-1
850,082 9^done
850,082 (gdb)
850,083 10set mem inaccessible-by-default off
set tcp auto-retry on
set tcp connect-timeout 30
850,083 11source .gdbinit
850,093 &"set mem inaccessible-by-default off\n"
850,093 =cmd-param-changed,param="mem inaccessible-by-default",value="off"
850,093 10^done
850,093 (gdb)
850,093 &"set tcp auto-retry on\n"
850,094 ^done
850,094 (gdb)
850,094 &"set tcp connect-timeout 30\n"
850,094 ^done
850,094 (gdb)
850,094 &"source .gdbinit\n"
850,095 &".gdbinit: No such file or directory.\n"
850,095 12-gdb-set auto-solib-add on
850,095 11^error,msg=".gdbinit: No such file or directory."
850,095 (gdb)
850,095 12^done
850,096 (gdb)
850,098 13-target-select remote localhost:7224
850,121 13^error,msg="Remote connection closed"
850,122 (gdb)
850,122 &"\n"
850,122 ^done
850,122 (gdb)
850,122 14-gdb-exit
850,132 14^exit
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++
Connection from "127.0.0.1" via 127.0.0.1
PE-ERROR: Target is not connected
Disconnected from "127.0.0.1" via 127.0.0.1
Target Disconnected.
++++++++++++++++++++++++++++++++++++++++++++++
Triyng to launch debug session:

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
474,011 2-gdb-version
474,017 ~"GNU gdb (GNU Tools for ARM Embedded Processors) 7.6.0.20140731-cvs\n"
474,017 ~"Copyright (C) 2013 Free Software Foundation, Inc.\n"
474,017 ~"License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\nThis is fre\
e software: you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitt\
ed by law. Type \"show copying\"\nand \"show warranty\" for details.\n"
474,017 ~"This GDB was configured as \"--host=i686-w64-mingw32 --target=arm-none-eabi\".\nFor bug re\
porting instructions, please see:\n"
474,017 ~"<http://www.gnu.org/software/gdb/bugs/>.\n"
474,018 2^done
474,018 (gdb)
474,019 3-environment-cd C:/Users/Mario/workspace.kds/prueba
474,027 3^done
474,027 (gdb)
474,027 4-gdb-set breakpoint pending on
474,037 4^done
474,037 (gdb)
474,037 5-enable-pretty-printing
474,047 5^done
474,047 (gdb)
474,047 6-gdb-set python print-stack none
474,057 6^done
474,057 (gdb)
474,057 7-gdb-set print object on
474,067 7^done
474,067 (gdb)
474,068 8-gdb-set print sevenbit-strings on
474,077 8^done
474,077 (gdb)
474,077 9-gdb-set charset ISO-8859-1
474,087 9^done
474,087 (gdb)
474,090 10set mem inaccessible-by-default off
set tcp auto-retry on
set tcp connect-timeout 30
474,090 11source .gdbinit
474,098 &"set mem inaccessible-by-default off\n"
474,098 =cmd-param-changed,param="mem inaccessible-by-default",value="off"
474,098 10^done
474,098 (gdb)
474,098 &"set tcp auto-retry on\n"
474,098 ^done
474,098 (gdb)
474,098 &"set tcp connect-timeout 30\n"
474,098 ^done
474,098 (gdb)
474,098 &"source .gdbinit\n"
474,098 &".gdbinit: No such file or directory.\n"
474,098 11^error,msg=".gdbinit: No such file or directory."
474,099 (gdb)
474,099 12-gdb-set auto-solib-add on
474,108 12^done
474,108 (gdb)
474,112 13-target-select remote localhost:7224
474,124 13^error,msg="Remote connection closed"
474,124 (gdb)
474,124 &"\n"
474,124 ^done
474,124 (gdb)
474,125 14-gdb-exit
474,134 14^exit
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
I can't connect to target.
However, I could mass erase one of my working boards succesfully:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
034,005 2-gdb-version
034,011 ~"GNU gdb (GNU Tools for ARM Embedded Processors) 7.6.0.20140731-cvs\n"
034,012 ~"Copyright (C) 2013 Free Software Foundation, Inc.\n"
034,012 ~"License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\nThis is fre\
e software: you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitt\
ed by law. Type \"show copying\"\nand \"show warranty\" for details.\n"
034,012 ~"This GDB was configured as \"--host=i686-w64-mingw32 --target=arm-none-eabi\".\nFor bug re\
porting instructions, please see:\n"
034,013 ~"<http://www.gnu.org/software/gdb/bugs/>.\n"
............
mo\
nitor trim 0
monitor partition 0
monitor preservepartition 0
034,219 &"monitor semihosting 0,51794\n"
034,221 @"Command Executed successfully: semihosting 0,51794\r\n"
034,221 16^done
034,221 (gdb)
034,221 &"monitor preserve0 0\n"
034,222 17symbol-file C:\\Users\\Mario\\workspace.kds\\prueba\\Debug\\prueba.elf
034,222 18load C:\\Users\\Mario\\workspace.kds\\prueba\\Debug\\prueba.elf
034,223 @"Command Executed successfully: preserve0 0\r\n"
034,223 ^done
034,223 (gdb)
034,223 &"monitor preserve1 0\n"
034,225 @"Command Executed successfully: preserve1 0\r\n"
034,225 ^done
034,225 (gdb)
034,225 &"monitor preserve2 0\n"
034,227 @"Command Executed successfully: preserve2 0\r\n"
034,227 ^done
034,227 (gdb)
034,227 &"monitor trim 0\n"
034,229 @"Command Executed successfully: trim 0\r\n"
034,229 ^done
034,229 (gdb)
034,229 &"monitor partition 0\n"
034,231 @"Command Executed successfully: partition 0\r\n"
034,231 ^done
034,231 (gdb)
034,231 &"monitor preservepartition 0\n"
034,234 @"Command Executed successfully: preservepartition 0\r\n"
034,234 ^done
034,234 (gdb)
034,234 &"symbol-file C:\\\\Users\\\\Mario\\\\workspace.kds\\\\prueba\\\\Debug\\\\prueba.elf\n"
034,235 ~"Reading symbols from C:\\Users\\Mario\\workspace.kds\\prueba\\Debug\\prueba.elf..."
034,236 ~"done.\n"
034,237 17^done
034,237 (gdb)
034,245 &"load C:\\\\Users\\\\Mario\\\\workspace.kds\\\\prueba\\\\Debug\\\\prueba.elf\n"
034,245 ~"Loading section .interrupts, size 0x1bc lma 0x0\n"
034,245 18+download,{section=".interrupts",section-size="444",total-size="477920"}
034,245 ~"Loading section .cfmprotect, size 0x10 lma 0x400\n"
034,245 18+download,{section=".cfmprotect",section-size="16",total-size="477920"}
034,245 ~"Loading section .text, size 0x564 lma 0x410\n"
034,245 18+download,{section=".text",section-size="1380",total-size="477920"}
034,245 ~"Loading section .ARM, size 0x8 lma 0x974\n"
034,245 18+download,{section=".ARM",section-size="8",total-size="477920"}
034,245 ~"Loading section .init_array, size 0x4 lma 0x97c\n"
034,245 18+download,{section=".init_array",section-size="4",total-size="477920"}
034,245 ~"Loading section .fini_array, size 0x4 lma 0x980\n"
034,246 19-gdb-show --thread-group i1 language
034,246 18+download,{section=".fini_array",section-size="4",total-size="477920"}
034,246 ~"Loading section .data, size 0x60 lma 0x984\n"
034,247 18+download,{section=".data",section-size="96",total-size="477920"}
034,247 ~"Loading section .romp, size 0x24 lma 0x9e4\n"
034,247 18+download,{section=".romp",section-size="36",total-size="477920"}
036,355 ~"Start address 0x688, load size 1988\n"
036,358 ~"Transfer rate: 939 bytes/sec, 220 bytes/write.\n"
036,386 18^done
036,387 (gdb)
036,387 19^done,value="auto"
036,388 (gdb)
036,389 20-gdb-set --thread-group i1 language c
036,398 20^done
036,398 (gdb)
036,399 21-interpreter-exec --thread-group i1 console "p/x (char)-1"
036,408 ~"$1 = 0xff\n"
036,408 21^done
036,408 (gdb)
036,409 22-data-evaluate-expression --thread-group i1 "sizeof (void*)"
036,418 22^done,value="4"
036,419 (gdb)
036,419 23-gdb-set --thread-group i1 language auto
036,428 23^done
036,428 (gdb)
036,429 24-interpreter-exec --thread-group i1 console "show endian"
036,438 ~"The target endianness is set automatically (currently little endian)\n"
036,438 24^done
036,439 (gdb)
036,452 25-break-insert --thread-group i1 -t -f C:\\Users\\Mario\\workspace.kds\\prueba\\Sources\\ma\
in.c:main
036,496 25^done,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x000004e8",func="ma\
in",file="../Sources/main.c",fullname="C:\\Users\\Mario\\workspace.kds\\prueba\\Sources\\main.c",lin\
e="47",thread-groups=["i1"],times="0",original-location="C:\\\\Users\\\\Mario\\\\workspace.kds\\\\pr\
ueba\\\\Sources\\\\main.c:main"}
036,497 (gdb)
036,504 26tbreak main
036,507 &"tbreak main\n"
036,512 ~"Note: breakpoint 1 also set at pc 0x4e8.\n"
036,515 ~"Temporary breakpoint 2 at 0x4e8: file ../Sources/main.c, line 47.\n"
036,515 =breakpoint-created,bkpt={number="2",type="breakpoint",disp="del",enabled="y",addr="0x000004\
e8",func="main",file="../Sources/main.c",fullname="C:\\\\Users\\\\Mario\\\\workspace.kds\\\\prueba\\\
\\Sources\\\\main.c",line="47",thread-groups=["i1"],times="0",original-location="main"}
036,516 26^done
036,516 (gdb)
036,517 27flushreg
continue
036,520 28-list-thread-groups
036,526 &"flushreg\n"
036,526 ~"Register cache flushed.\n"
036,536 27^done
036,536 (gdb)
036,537 &"continue\n"
036,537 ~"Continuing.\n"
036,539 ~"Note: automatically using hardware breakpoints for read-only addresses.\n"
036,540 ^running
036,540 *running,thread-id="all"
036,540 (gdb)
036,575 =breakpoint-modified,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x00000\
4e8",func="main",file="../Sources/main.c",fullname="C:\\\\Users\\\\Mario\\\\workspace.kds\\\\prueba\\
\\\Sources\\\\main.c",line="47",thread-groups=["i1"],times="1",original-location="C:\\\\\\\\Users\\\\
\\\\\Mario\\\\\\\\workspace.kds\\\\\\\\prueba\\\\\\\\Sources\\\\\\\\main.c:main"}
036,575 =breakpoint-modified,bkpt={number="2",type="breakpoint",disp="del",enabled="y",addr="0x00000\
4e8",func="main",file="../Sources/main.c",fullname="C:\\\\Users\\\\Mario\\\\workspace.kds\\\\prueba\\
\\\Sources\\\\main.c",line="47",thread-groups=["i1"],times="1",original-location="main"}
036,576 ~"\nTemporary breakpoint "
036,581 ~"1, main () at ../Sources/main.c:47\n"
036,581 ~"47\t PE_low_level_init();\n"
036,582 *stopped,reason="breakpoint-hit",disp="del",bkptno="1",frame={addr="0x000004e8",func="main",\
args=[],file="../Sources/main.c",fullname="C:\\Users\\Mario\\workspace.kds\\prueba\\Sources\\main.c"\
,line="47"},thread-id="1",stopped-threads="all"
036,582 =breakpoint-deleted,id="1"
036,582 =breakpoint-deleted,id="2"
036,582 (gdb)
036,583 28^done,groups=[{id="i1",type="process",pid="42000"}]
036,585 (gdb)
037,539 29-gdb-exit
037,543 29^exit
037,543 =thread-group-exited,id="i1"
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Connection from "127.0.0.1" via 127.0.0.1
Copyright 2012 P&E Microcomputer Systems,Inc.
Command Line :C:\Freescale\KDS_3.0.0\eclipse\plugins\com.pemicro.debug.gdbjtag.pne_2.0.8.201504092111\win32\pegdbserver_console -device=Freescale_K2x_K20DX256M7 -startserver -singlesession -serverport=7224 -interface=USBMULTILINK -speed=5000 -port=USB1 -
CMD>RE
Initializing.
Target has been RESET and is active.
CMD>CM C:\Freescale\KDS_3.0.0\eclipse\plugins\com.pemicro.debug.gdbjtag.pne_2.0.8.201504092111\win32\gdi\P&E\supportFiles_ARM\Freescale\K2x\freescale_k20dx256m7_pflash_dflash_eeprom.arp
Initializing.
Initialized.
;version 1.05, 06/02/2014, Copyright 2014 P&E Microcomputer Systems, Inc. All rights reserved. www.pemicro.com [mk_256k_dx_pflash_dflash_eeprom_p1]
;device freescale, k20dx256m7, pflash_dflash_eeprom
;begin_cs device=$00000000, length=$14000800, ram=$20000000
Loading programming algorithm ...
Done.
CMD>EM
Erasing.
Module has been erased.
Initializing.
Initialized.
;version 1.05, 06/02/2014, Copyright 2014 P&E Microcomputer Systems, Inc. All rights reserved. www.pemicro.com [mk_256k_dx_pflash_dflash_eeprom_p1]
;device freescale, k20dx256m7, pflash_dflash_eeprom
;begin_cs device=$00000000, length=$14000800, ram=$20000000
Loading programming algorithm ...
Done.
CMD>PM
Programming.
Processing Object File Data ...
Programmed.
CMD>VC
Verifying object file CRC-16 to device ranges ...
block 00000000-000001BB ...
Ok.
block 00000400-00000A07 ...
Ok.
Checksum Verification Successful. (Cumulative CRC-16=$0778)
CMD>RE
Initializing.
Target has been RESET and is active.
Preset breakpoint encountered.
Disconnected from "127.0.0.1" via 127.0.0.1
Target Disconnected.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Also, I can launch example program I have created.
I have a question, If devices are secured? All of them are secured at the beginning?
If no, I think I have good luck with 2 of my chips but no the same with others 4.
I re-checked (again) my connections, and everything is ok, the circuit is in the same conditions that my working boards.
Sorry for too long text,
Thank you Pascal.
Mario