Error: [Common 17-36] Cannot write file [project_constraints.ucf]

http://forums.xilinx.com/t5/Hierarchical-Design/PlanAhead-cannot-write-to-ucf-during-runs/td-p/271092


I ran into this when I was copying over projects and just modifying the constraints. The solution is to: A workaround for this specific issue is to uncheck "Read- only" for the UCF file that resides in the folder <project_name>.runs/impl_1/.constrs

>> 11/25 Update

Okay this also sometimes happens to me even when the Read-Only IS unchecked, when that happens, I saw one poster that deleted the folder for the run (impl_1 typically) I just made a new run and it will go.

UART not responding on working SDK project and Bitstream

When you need UARTs to connect to peripheral devices as well as UARTs to the terminal, you can run into many confusing situations. In my case I was getting no UART output. One of the things that worked for me was modifying the bsp settings

See the steps below:

Program FPGA Failed: DONE bit didn't go high after programming FPGA

So I ran into this problem for the first time today:

The issue ended up being that while debugging I had to relaunch the SDK and it auto defaulted to the wrong bitfile, so the entire time I was attempting to program the wrong bitstream.

This can also happen if you were previously automatically booting from Linux like with a NAND or something, just program again 

Failed to launch program edif2ngd

[NgdBuild 527] Failed to launch program edif2ngd: The pipe has been ended.

[NgdBuild 28] edif2ngd did not successfully complete.  Please check preceding errors for root cause.

 

This error sucked. Turns out you just need to re-launch the implementation run again. Didn't do anything special.

 

FPGA configuration encountered errors. Program FPGA failed

In this case the solution was actually simple. The console window was actually displaying something like this:

The following sections did not fit into Processor BRAM memory:
Section .jcr (0x88000944 - 0x88000947)
Section .eh_frame (0x88000940 - 0x88000943)
Section .data (0x88000830 - 0x8800093F)
Section .rodata (0x88000814 - 0x88000829)
Section .dtors (0x8800080C - 0x88000813)
Section .ctors (0x88000804 - 0x8800080B)
Section .fini (0x880007E8 - 0x88000803)
Section .init (0x880007B4 - 0x880007E7)
Section .text (0x88000000 - 0x880007B3)

Try using the linker script generation tools to generate an ELF that maps
correctly to your hardware design.

Which is a common error. Normally you can just make the BRAM larger in the EDK and regenerate. If it is still not working other things to try:

Booting from somewhere else:
 http://www.xilinx.com/support/answers/43414.htm
Turning off ELF check if the ELF is too large:
http://www.xilinx.com/support/answers/38178.html
Completely deleting Linker Script and regenerating:
http://forums.xilinx.com/t5/Embedded-Development-Tools/elfcheck-failed/td-p/307699
"It looks like it's still trying to place the data and code into your BRAM.  Double check your linker script generation and manually delete the .ld file before rebuilding the workspace."

Failed to connect to Xilinx hw_server

Program FPGA failed

Reason:

   Failed to connect to Xilinx hw_server. Check if the hw_server is running and correct TCP port is used.

http://www.xilinx.com/support/answers/55431.htm

hw_server is used with the TCF infrastructure for debugging and it only supports Digilent and has to be launch manually from a shell.

The 'Auto Detect' option always chooses the TCF flow when the Digilent cable is plugged in.

If you do not want to use the TCF infrastructure, you must change the JTAG cable pull-down menu from Auto Detect to 'Digilent USB Cable' and resolve the error.

This change is found from SDK's Xilinx Tools -> Configure JTAG Settings. Again, changing from Auto Detect to Digilent USB Cable resolves the issue.

Editing Telemetry Packets for Vector File Testbench in Word

So I you have a packet that looks like this:

AA BB CC DD  11 22 33 44

And you need it to be in a vector read-in format for the simulator

AA
BB
CC
DD
11
22
33
44

You can actually use word find and replace. In this case replace any Two space with just one. And then replace all spaces with ^l

You can also find this setting under the "Special Characters" Button at the bottom of the Find and Replace Menu.

Also note you can use CTRL+SHIFT+8 to see the editing special characters