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Visitor aeneas32
Visitor
5,267 Views
Registered: ‎10-08-2014

"Cannot access JTAG-DP" on Zybo getting started scenario

Followed the Zybo Getting Started scenario with Vivado and then SDK,

Program FPGA results in "Done" light going on.

However,  the  Run As→Launch on Hardware(GDB)   results in error message

"  Unexpected error while launching program: Error while running ps7_init method.
   Cannot write to target
      Cannot access JTAG-DP: invalid ACK value (0x00, expected=0x02)
      Error Address = 0xf800074c   "

Jumpered for USB power, with both the USB and the micro-USB plugs connected to laptop,

which together cause  PGOOD  to be lit on.

JP5 jumpered for JTAG.

What is causing this .elf  "Cannot write" error, when the prior Program FPGA does result in Done success ?

Tags (3)
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7 Replies
Moderator
Moderator
5,250 Views
Registered: ‎07-31-2012

Re: "Cannot access JTAG-DP" on Zybo getting started scenario

Hi,

 

Please refer to this thread if it helps you https://forums.xilinx.com/t5/Embedded-Processor-System-Design/Problems-getting-a-new-Zynq-board-up-and-running/td-p/364059

<OR>

This could happen if you have your boot mode switches set to boot from some non-volatile memory first which boots and then you try to connect over jtag and run ps7_init

 

Regards

Praveen


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Moderator
Moderator
5,236 Views
Registered: ‎04-17-2011

Re: "Cannot access JTAG-DP" on Zybo getting started scenario

Just to add, do use the System Debugger for Zynq based designs.
Run As -> Launch on Hardware (System Debugger)
Regards,
Debraj
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Visitor aeneas32
Visitor
5,226 Views
Registered: ‎10-08-2014

Re: "Cannot access JTAG-DP" on Zybo getting started scenario

That link talks about current from the power source,

whereas my setup is based on USB current through a laptop,

and I have also tried a USB Hub with a 2A power supply plugged into the usb hub.

The simple issue is the difference between what the PCB trying to do with Program FPGA

which succeeds with the Done light lit,

and then the Run As...Launch On Hardware(GDB), which fails ?

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Visitor aeneas32
Visitor
5,217 Views
Registered: ‎10-08-2014

Re: "Cannot access JTAG-DP" on Zybo getting started scenario

I already tried that.

When using the Run As...System Debugger,  the error is:

" Error while launching program:
Invalid DAP ACK value: 0  "

What causes this error and again, what distinguishes the action attempted here,

from the Program FPGA action, which succeeds ?

Tags (1)
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Moderator
Moderator
5,197 Views
Registered: ‎04-17-2011

Re: "Cannot access JTAG-DP" on Zybo getting started scenario

Check the BOOT Mode pins. Read the register- 0xF800025C (slcr.BOOT_MODE). Refer Table 6-4 from the TRM: http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf

Check BOOT_MODE[3] pin setting and ensure it is not in Independent mode. That setting should have a value of 0. If you have hard-wired the BOOT_MODE pins then you need to check what is the value you have assigned to it and post back here.
Regards,
Debraj
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Visitor aeneas32
Visitor
5,186 Views
Registered: ‎10-08-2014

Re: "Cannot access JTAG-DP" on Zybo getting started scenario (Invalid DAP ACK value: 0)

-----------------------------------------
XSDB
-----------------------------------------
Program FPGA
(success, with Done light on)
-----------------------------------------
100%    1MB   1.9MB/s  00:01 
----------------------------------------- 
mrd 0xF800025C
xsdb% Context does not support memory read. Unsupported command
-----------------------------------------
System Debugger on Local   app.elf
-----------------------------------------
Info: ARM Cortex-A9 MPCore #0 (target 2) Stopped at 0xffffff28 (Suspended)
Info: ARM Cortex-A9 MPCore #1 (target 3) Stopped at 0xffffff34 (Suspended)
-----------------------------------------
Error while launching program:
Invalid DAP ACK value: 0
-----------------------------------------
mrd 0xF800025C
F800025C:   00000000
-----------------------------------------

 

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Observer marinejavier
Observer
1,417 Views
Registered: ‎06-25-2017

Re: "Cannot access JTAG-DP" on Zybo getting started scenario

Hi to everyone.

 

I am trying to running the "hello world" example. on the Zybo.

In vivado I used just the : Zynq IP bloq with the configuration for Zybo, After that I launch SDK and execute "hello World" example, I recieved the same message.

 

"Cannot access JTAG-DP: invalid ACK value (0x00, expected=0x02) Error Address = 0xf8000768"

 

I found the problem and I hope it can help to another one.

In my case the message come from the Zynq setting. Below you can see a capture with the problem solved.

 

Best regards.

zybo_problem.png
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