FPGA Configuration

USB Configuration

The easiest way to configure the FPGA is to use the on-board USB configuration circuit. This circuit emulates a Xilinx Platform USB Cable, the drivers for which are included with Xilinx ISE and WebPack. To use this interface, connect the WARP FPGA Board's USB port directly to your PC using a standard USB cable. The first time you connect a board to your PC, Windows will prompt you to search for and install drivers, possibly multiple times. Allow Windows to complete this process before attempting to configure the FPGA.

The WARP FPGA board's USB connector is on the back of the board and is highlighted in the image above.

External JTAG Cable

Some PCs do not support the USB configuration circuit on the FPGA board. Windows Server 2003, for example, is incompatible with Xilinx's USB drivers. In these situations, you can configure the FPGA using an external Xiilnx JTAG cable. The WARP FPGA board has a standard JTAG connector which is compatible with both the Xilinx Parallel IV and Platform USB cables.

The WARP FPGA board's JTAG connector is on the back of the board and is highlighted in the image above. On the board this connector is component J53 labaled 'SysACE JTAG'.

SystemACE CompactFlash

The WARP FPGA board also includes Xilinx's SystemACE CompactFlash chip for managing the configuration process of the FPGA. The SystemACE chip acts as an interface between the FPGA and a standard CompactFlash slot.

The SystemACE automatically configures the FPGA on powerup or when the manual reset button is pushed. Multiple configuration files can be stored on the CF card. The SystemACE chip reads a 3-bit address from a DIP switch to choose one of eight configuration files. The fourth position on the DIP switch, labeled CFGMODE, should generally be set to 1 (slid to the right). The figure below illustrates the DIP switch positions to select the desired configuration file.

Two LEDs indicate the status of the SystemACE controller. The green LED (D12) will glow when the controller has successfully configured the FPGA using a bitstream on the CompactFlash card. The red LED (D9) will glow when an error occurs during configuration from the CF card. This is usually due to format problems on the card or errors in the configuration files. When no CF card is inserted, neither LED will glow. If the FPGA has already been configured, either via CF or JTAG, it will retain this configuration even after you remove the CF card.

Xilinx iMPACT must be used to convert .bit files to SystemACE .ace files and to construct the CF card file system.

Other References

Last modified 15 years ago Last modified on Oct 17, 2009, 10:16:30 PM