Re: [Openocd-development] Warn : Unexpected idcode after end of chain: 0x00000000 and Info : TAP does not have IDCODE

[David B. <da...@pa...>]

> > All these zeroes suggest either a TAP which
> > legitimately has no IDCODE instruction support
> > (and thus looks like IDCODE == 0) ...
> >
> >  ... OR else hardware problems somewhere in the
> > JTAG chain, possibly in some other TAP.
> >
> 
> Hello David,
> I am not so sure about this. Still smells like reset
> problem to me.

That could be the "hardware problems..." case.

Recall that TRST (JTAG reset) is supposed to put
the scan chain in a sane state -- not "all zeroes".

Is TRST wired up?  And configured, so OpenOCD wil
use it?  Or is it using the JTAG state machine entry
to that state?

Do you know that your chip (sometime you should post
your config) handles SRST correctly (it should not
affect JTAG), but you still might want to enable it.