Xilinx 1000BASE-X Manual de usuario Pagina 92

  • Descarga
  • Añadir a mis manuales
  • Imprimir
  • Pagina
    / 230
  • Tabla de contenidos
  • MARCADORES
  • Valorado. / 5. Basado en revisión del cliente
Vista de pagina 91
92 www.xilinx.com Ethernet 1000BASE-X PCS/PMA or SGMII v9.1
UG155 March 24, 2008
Chapter 7: 1000BASE-X with RocketIO Transceivers
R
Virtex-5 FXT Devices
Figure 7-8 illustrates sharing clock resources across multiple instantiations of the core
when using Virtex-5 RocketIO GTX transceivers.
The example design can be generated to connect either a single instance of the core or
connect a pair of core instances to the transceiver pair present in a GTX tile. Figure 7-8
illustrates two instantiations of the block level, and each block level contains a pair of
cores, consequently illustrating clock sharing between a total of four cores.
Additional cores can be added by continuing to instantiate extra block level modules.
Share the brefclk_p and brefclk_n differential clock pair. See the Virtex-5 RocketIO
GTX Transceiver User Guide for more information.
To provide the FPGA fabric clocks for all core instances, select a REFCLKOUT port from any
GTX transceiver and route this to a single DCM. The CLK0 (125MHz) and CLKDV
(62.5MHz) outputs from this DCM, placed onto global clock routing using a BUFGs, can be
shared across all core instances and GTX transceivers as illustrated.
Vista de pagina 91
1 2 ... 87 88 89 90 91 92 93 94 95 96 97 ... 229 230

Comentarios a estos manuales

Sin comentarios