xga timing
Try inside Spartan3 Starter Kit reference design materials. innside Microblaze pack there are part with simple VGA (not very useful) but in one of the design files (svga_timing.vhd) you can find an information about many video modes with detailed parameters (horizontal and vertical freq, front and back porch's etc.) for generating video frames. I have used this values in my design with succes on LCD and CRT monitors.
The link to the resources:
**broken link removed**