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

[Laurent G. <lau...@am...>]

>
> Hello David,
> I am not so sure about this. Still smells like reset problem to me.
>
> It should be noted that when I let small bootloader execute from the
> SPI flash and do the reset (and some other config), I can attach  with
> OpenOCD, i.e. chain is well scanned. I was able after attachment to
> set-up SDRAM and launch eCos application (which would further
> configure SoC). Now I erased the flash and tried without bootloader. I
> do not exactly know what bootloader is doing (have not insight in the
> code yet), but obviously nothing expect reset is needed for a proper
> chain scanning.
>
> It should be also noted that Lauterbach jtag attaches without any
> problems. I do not think that it does anything special for this step.
> All what is needed after is few lines of SDRAM set-up and application
> can be uploaded and run. But that comes after attachment (as for
> OpenOCD).
>
> All this confirms that hardware is working properly. I am almost
> convinced that bug is either on OpenOCD side (I tried with both ftd
> libs) or I should configure reset in some special way...
>
> Would anybody have some hints after these additional explanations ?
>
> Best regards,
> Drasko
>   
It is not coming from your JTAGkey-2 since you can scan and detect the 
chain after configuration of your system.

It is really somewhere in the OpenOCD .

But you could try to disable the use of RTCK feature from the Amontec 
JTAGkey-2 and run at a super low frequency before doing your scan chain 
detection.

Also, could you please try to disconnect the JTAGkey from USB port 
before doing this. OpenOCD is still not really clean regarding the 
finish using the Amontec JTAGey as other FT2232 USB JTAG dongle before 
closing its handle in mpsse mode.

The sequence before closing the JTAGkey as other FT2232 USB JTAG dongle 
should be :
- 1. place all pin as input
- 2. quit the mppse bitbang mode
- 3. close the handle

CLEAN AFTER COMING :-)

the 1. and 2. are NOT DONE in the actual OpenOCD and it can make trouble 
when you close and re-open the openocd.

Let us know the debug output in this case.

Regards,
Laurent

 http://www.amontec.com
 Amontec USB JTAG cable suite : JTAGkey JTAGkey-2 JTAGkey-3 ( coming 
soon with SWD support )