[OpenOCD-user] Error: JTAG scan chain interrogation failed: all zeroes

[ravi k. <rav...@gm...>]

Hello actuallly im trying to interface SAML21Xplained pro board for Jtag
Communication with JtagBoard provided by ngxtechnologies through openocd
server. But when im trying to access the board it is responding with an
JTAG scan chain interrogation failed: all zeroes. I have interfaced the
sama5d36 and sama5d2 xplained board with the same Jtag Debugger with both
the boards it is working. Someone Please help me to come out of this
problem...and give me some some conclusion wheather saml21 board can be
used with jtag for bebugging. Please find the attached documenet for the
config file

config for target device saml21 board
```
#
# script for Atmel SAMD, SAMR, SAML or SAMC, a Cortex-M0 chip
#
#
# samdXX devices only support SWD transports.
#
source [find target/swj-dp.tcl]

if { [info exists CHIPNAME] } {
   set _CHIPNAME $CHIPNAME
} else {
   set _CHIPNAME at91saml21j18
}

if { [info exists ENDIAN] } {
   set _ENDIAN $ENDIAN
} else {
   set _ENDIAN little
}

# Work-area is a space in RAM used for flash programming
# By default use 2kB
if { [info exists WORKAREASIZE] } {
   set _WORKAREASIZE $WORKAREASIZE
} else {
   set _WORKAREASIZE 0x800
}

if { [info exists CPUTAPID] } {
   set _CPUTAPID $CPUTAPID
} else {
   set _CPUTAPID 0x4ba00477
}

swj_newdap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
dap create $_CHIPNAME.dap -chain-position $_CHIPNAME.cpu

set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME cortex_m -endian $_ENDIAN -dap $_CHIPNAME.dap

$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size
$_WORKAREASIZE -work-area-backup 0

# SAMD DSU will hold the CPU in reset if TCK is low when RESET_N
# deasserts (see datasheet Atmel-42181E–SAM-D21_Datasheet–02/2015, section
12.6.2)
#
# dsu_reset_deassert configures whether we want to run or halt out of reset,
# then instruct the DSU to let us out of reset.
$_TARGETNAME configure -event reset-deassert-post {
        at91saml21j18 dsu_reset_deassert
}

# SRST (wired to RESET_N) resets debug circuitry
# srst_pulls_trst is not configured here to avoid an error raised in reset
halt
reset_config srst_gates_jtag

# Do not use a reset button with other SWD adapter than Atmel's EDBG.
# DSU usually locks MCU in reset state until you issue a reset command
# in OpenOCD.

# SAMD runs at SYSCLK = 1 MHz divided from RC oscillator after reset.
# Other members of family usually use SYSCLK = 4 MHz after reset.
# Datasheet does not specify SYSCLK to SWD clock ratio.
# Usually used SYSCLK/6 is slow, testing shows that debugging can
# work @ SYSCLK/2 but your mileage may vary.
# This limit is most probably imposed by incorrectly handled SWD WAIT
# on some SWD adapters.

adapter_khz 400

# Atmel's EDBG (on-board cmsis-dap adapter of Xplained kits) works
# without problem at maximal clock speed. Atmel recommends
# adapter speed less than 10 * CPU clock.
# adapter_khz 5000

if {![using_hla]} {
   # if srst is not fitted use SYSRESETREQ to
   # perform a soft reset
echo "----------"
   cortex_m reset_config sysresetreq
}



```

--------check the below logs for error--------

```
root@yash01-desktop:/home/yash01/Videos/code/tcl# openocd -f
interface/ftdi/ngxtech.cfg -f board/atmel_saml21_xplained_pro.cfg
Open On-Chip Debugger 0.10.0+dev-00735-g56568b7-dirty (2019-06-10-18:27)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
WARNING!
This file was not tested with real interface, but is assumed to work as this
interface uses the same layout as configs that were verified. Please report
your
experience with this file to openocd-devel mailing list, so it could be
marked
as working or fixed.
Warn : Interface already configured, ignoring
Info : auto-selecting first available session transport "jtag". To override
use 'transport select <transport>'.
none separate
adapter speed: 400 kHz
----------
cortex_m reset_config sysresetreq
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 400 kHz
Error: JTAG scan chain interrogation failed: all zeroes
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Error: at91saml21j18.cpu: IR capture error; saw 0x0 not 0x1
Warn : Bypassing JTAG setup events due to errors
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
Error: Invalid ACK (0) in DAP response
```