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

[Andreas F. <and...@gm...>]

On Wed, Jun 26, 2019 at 2:16 PM ravi kiran <rav...@gm...> wrote:

> # script for Atmel SAMD, SAMR, SAML or SAMC, a Cortex-M0 chip
> #
> #
> # samdXX devices only support SWD transports.
>

The config file says it. The chip doesn't support JTAG. So you'll need to
have an adapter that can speak SWD (the NGX one doesn't), and you'll need
to specify SWD as the transport *before* sourcing the target config file.

For example:

openocd -f interface/your-swd-capable-adapter.cfg -c "transport select swd"
-f target/at91samdXX.cfg

Note that you have an additional problem in your command line; you're
sourcing a board file for a board that has an integrated debug adapter, but
you have already sourced an adapter file. If you don't have that exact
board, source the target file directly, as above. If you do have that
Xplained board, then why do you use an external debug adapter?

/Andreas