The following buffers are available for use with your clocks in the Virtex-6 FPGA designs:
- BUFIO
- BUFR
- BUFG/BUFGCTRL/BUFGMUX
- BUFH
BUFIO/BUFR The BUFIO/BUFR buffers are used for regional clocks that do not need to reach all regions of the device.They are typically used for clocking IOSERDES interfaces.If you would like additional information on how to use either of these two buffers, you can find this informationin theRegional Clocking Resources sectionof the
Virtex-6 Clocking Resources Users Guide (UG362):
http://www.xilinx.com/support/documentation/user_guides/ug362.pdf BUFG/BUFGCTRL/BUFGMUX The BUFG/BUFGCTRL/BUFGMUX are used for Global clocks that need to reach logic throughout the entire device. You can only reach the BUFG buffers through a special Global Clock pin (GCLK pin). If you would like more information regarding how to use the BUFG buffers, you can find this informationin the Global Clocking Resources section of the
Virtex-6 Clocking Resources Users Guide (UG362):
http://www.xilinx.com/support/documentation/user_guides/ug362.pdf BUFH The horizontal clock buffer (BUFH) is a buffer that drives a horizontal global clock tree spine in a single region. These buffers include a clock enable that can be used to dynamically turn the clock network on or off. This allows you to conserve power by giving you the ability to turn off regions of logic that are not in use. For more information on how to use the BUFH buffer, you can find this information in the Regional Clocking Resources section of the
Virtex-6 Clocking Resources Users Guide (UG362):
http://www.xilinx.com/support/documentation/user_guides/ug362.pdf