Configuration Bitstream Readback over JTAG issues

[pavel_47]

Hello,

Since a few days I try to implement readback procedure from UG470 (pp. 135...137, Table 6-5) using ZC706 board.

Doesn't work. All read values are '0'.

Well ... Table 6-5 describes a particular type of readback: Shutdown Readback Command Sequence.

I don't want shutdown the board, so I removed step 4.

At the beginning of the chapter 6 of UG470 (chapter, where Table 6-5  is located) there is section named Preparing a Design for Readback.

Here is extract from this section:

There are two mandatory bitstream settings for readback: the security setting must not
prohibit readback (security:none), and bitstream encryption must not be used.

Where can I set these two options, i.e. security and encryption.

Thanks.

[pavel_47]

Well ... I've found it:

It is set to NONE meaning that there is no any security and readback should work.

But it doesn't work.

I didn't find encryption option ... but given that all readback values are '0' it seems that the encryption has nothing to do with this issue.

Any suggestions ?

Thanks.

[pavel_47]

I'm wondering ... does exist some TCl command/instruction in Vivado or SDK that provides bitstream readback.

That way one could "sniff" the right sequence on JTAG lines.

Thanks.

[andresb]

Hi pavel,

The TCL command is:

readback_hw_device -bin_file readback_test.bin

It's in the Vivado Programming and Debugging User Guide:

https://www.xilinx.com/support/documentation/sw_manuals/xilinx2017_1/ug908-vivado-programming-debugging.pdf

Thanks,

Andres

[pavel_47]

Thanks !

[abin]

I also encountered the same problem, how can you solve it?