BitGen produces a bitstream for Xilinx device configuration. After the design has been completely routed, it is necessary to configure the device so that it can execute the desired function. This is done with BitGen, Xilinx's bitstream generation program. BitGen takes a fully routed NCD (Circuit Description) file as its input and produces a configuration bitstream - a binary file with a .bit extension.
The BIT file contains all of the configuration information from the NCD file defining the internal logic and interconnections of the FPGA, plus device-specific information from other files associated with the target device. The binary data in the BIT file can then be downloaded into the FPGA's memory cells or it can be used to create a PROM file (see the “PROMGen” chapter).
Figure 13.1 BitGen |  |
