UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 19112

LogiCORE OPB 10/100 Ethernet MAC / MII to RMII - What are the constraints required for the OPB 10/100 EMAC core when used with the MII to RMII interface?

Description

Description:

What are the constraints required for the OPB 10/100 EMAC core with the MII_to_RMII interface?

Solution

The following constraints are needed when the OPB 10/100 EMAC core is used with the MII to RMII interface:

NET "Ref_Clk" TNM_NET = "Ref_Clk_GRP";

TIMESPEC "TSTXOUT" = FROM "Ref_Clk_GRP" TO "PADS" 5 ns;

TIMESPEC "TSRXIN" = FROM "PADS" TO "Ref_Clk_GRP" 3 ns;

NET "Ref_Clk" USELOWSKEWLINES;

NET "Rmii2Mac_tx_clk" USELOWSKEWLINES;

NET "Rmii2Mac_rx_clk" USELOWSKEWLINES;

NET "Ref_Clk" MAXSKEW= 1.0 ns;

NET "Rmii2Mac_tx_clk" MAXSKEW= 1.0 ns;

NET "Rmii2Mac_rx_clk" MAXSKEW= 1.0 ns;

NET "Ref_Clk" PERIOD = 20 ns HIGH 6 ns;

NET "Rmii2Mac_tx_clk" PERIOD = 40 ns HIGH 18 ns;

NET "Rmii2Mac_rx_clk" PERIOD = 40 ns HIGH 18 ns;

NET "Phy2Rmii_rxd<1>" NODELAY;

NET "Phy2Rmii_rxd<0>" NODELAY;

NET "Phy2Rmii_crs_dv" NODELAY;

NET "Phy2Rmii_rx_er" NODELAY;

NOTE: The MAXSKEW of 1.0 ns may be difficult to meet. If so, increase the skew to 1.5 or 2 ns.

NOTE:

These are the typical constraints for the OPB 10/100 Ethernet core. These constraints are no longer needed.

NET "PHY_rx_clk" TNM_NET = "RXCLK_GRP";

NET "PHY_tx_clk" TNM_NET = "TXCLK_GRP";

TIMESPEC "TSTXOUT" = FROM "TXCLK_GRP" TO "PADS" 10 ns;

TIMESPEC "TSRXIN" = FROM "PADS" TO "RXCLK_GRP" 6 ns;

NET "phy_rx_clk" USELOWSKEWLINES;

NET "phy_tx_clk" USELOWSKEWLINES;

NET "PHY_tx_clk" MAXSKEW= 1.5 ns;

NET "PHY_rx_clk" MAXSKEW= 1.5 ns;

NET "PHY_rx_clk" PERIOD = 40 ns HIGH 14 ns;

NET "PHY_tx_clk" PERIOD = 40 ns HIGH 14 ns;

NET "PHY_rx_data<3>" NODELAY;

NET "PHY_rx_data<2>" NODELAY;

NET "PHY_rx_data<1>" NODELAY;

NET "PHY_rx_data<0>" NODELAY;

NET "PHY_dv" NODELAY;

NET "PHY_rx_er" NODELAY;

AR# 19112
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article