Saturday, September 1, 2012

Xilinx Zynq - harder to implement than one would hope

So I get a new Zynq ZC702 development board, and I'm tasked with making it work. I got the new ISE 14.2 development tools from Xilinx. Here are some things you might want to know if you encounter the same board.

The FPGA logic is the PL (Programming Logic), and the A9 subsystem is the PS (Processor System). Don't attempt to use Impact to burn anything! The burning is all done through an application called zynq_flash.exe.

Do not use Project Navigator to build this FPGA bitstream! Even if you wanted to, which I did, you will find that ngdbuild crashes most of the time (when using the embedded A9) in this flow. Use PlanAhead. It is the new recommended flow from Xilinx. Its also a surprisingly good flow.

The flow I'm using is:
Create a project in XPS. Set up everything that you need for interfacing to the PL there.
Export the project for the SDK, it's an option in XPS. Don't generate the bitstream. Don't launch the SDK.
Create a new project in PlanAhead. Import the .xmp project that you created in XPS. Right click on the embedded processor to create a stub file. Add your source files, and build the rest of the project there.
Generate a bitstream.
Open SDK. Create a new hardware platform specification. Browse for the .XML file under the XPS project in the SDK export folder. Choose the bitstream that was built by PlanAhead. If you have a .bmm file, then use it.
Create a new BSP based on this platform.
Create a new C project and choose Zynq FSBL. You need the FSBL (First Stage Bootloader) to burn the FPGA. It is also needed by the A9 to boot up. Select the platform that you created for the FSBL.
Create a project for your application based on the platform you created.

To burn, right click on the application, and choose to create image. It will automatically add the FSBL, bitstream, and application. To burn the new .mcs file, use the Xilinx tools menu, and burn flash. This is using the zynq_flah applicaion.

Some caveats, I have seen zynq_flash claim to burn even when it doesn't. If the erase step doesn't take at least a few seconds (more like 30+), then it's not working. I have never seen the verify option work at all. If it isn't burning, then turn off the board for a few minutes, and try again.

That's about it.

1 comment:

  1. This may be of use to you:

    It outlines the recommended flow for creating a Zynq-7000 project with the 14.2 tools.