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?

描述

Description:

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

解决方案

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
日期 12/15/2012
状态 Active
Type 综合文章