Platform Studio

Downloading Bitstreams to an FPGA

If your embedded system is a submodule in a top-level Xilinx® Integrated Software Environment (ISE™) design, use the Xilinx® iMPACT tool in Project Navigator to connect to your target FPGA and download the bitstream. Otherwise, you can use Xilinx® Platform Studio (XPS) in stand-alone mode to run iMPACT for you. To download the design, you must first set up the board and the parallel cable as required. For instructions on cabling, see the Procedures > Configuring Devices section of the help system for iMPACT.

To Download and Execute the Selected Design

When you select Device Configuration > Download Bitstream, XPS downloads the bitstream (download.bit file) onto the target board using iMPACT in batch mode. XPS uses the file etc/download.cmd for downloading the bitstream. Because XPS tools are makefile based, the download button calls on the makefile and executes the steps necessary to create the bitstream with the Executable Linked Format (ELF) file populated within the bitstream.

Note The file system.bit, created after hardware generation (completion of Xflow), is an uninitialized bitstream and does not include the ELF file. It is only when you execute the command to download or update the bitstream that the system.bit and ELF files merge into download.bit.

The XPS routine for generating the bitstream might vary, depending on where you are in the flow. For example, if Platgen has not been run, the download command runs all the tools (Platgen, Xflow, Libgen, GCC, and BitInit) to generate the bitstream. Or, if some tools have been run already, such as Platgen and Xflow, the download command runs only those tools needed to generate the bitstream.

In general, the download command relies on the file etc/download.cmd, which is the iMPACT command to download a bitstream. The command calls the makefile and runs iMPACT from a command line to download the populated bitstream to the target board.

Downloading the bitstream brings the processor out of reset and starts execution.

What to Do Next

Running an Application from External Memory