Xilinx 1000BASE-X manual Idelay

Models: 1000BASE-X

1 230
Download 230 pages 37.04 Kb
Page 74
Image 74

R

Chapter 6: The Ten-Bit Interface

Method 2

This logic from method 1 relies on pma_rx_clk0 and pma_rx_clk1 being exactly 180 degrees out of phase with each other since the falling edge of pma_rx_clk0 is used in place of pma_rx_clk1. See the data sheet for the attached SERDES to verify that this is the case. If not, then the logic of Figure 6-5illustrates an alternative implementation where both pma_rx_clk0 and pma_rx_clk1 are used as intended. Each bit of rx_code_group[9:0] must be routed to two separate device pads.

Ethernet 1000BASE-X PCS/PMA

or SGMII LogiCORE

IOB LOGIC

pma_rx_clk0

BUFG

IDELAY

pma_rx_clk0_bufg

(62.5 MHz)

IOB LOGIC

IBUFG

IBUF

pma_rx_clk0

IPAD

rx_code_group0[0]

rx_code_group0_reg[0] Q D IDELAY

rx_code_group[0]

IPAD

IOB LOGIC

pma_rx_clk1

BUFG

IDELAY

pma_rx_clk1_bufg

(62.5 MHz)

IOB LOGIC

IBUFG

IBUF

pma_rx_clk1

IPADrx_code_group[0]

rx_code_group1[0]

rx_code_group1_reg[0] Q D IDELAY

rx_code_group[0]

IPAD

Figure 6-5:Alternate Ten-Bit Interface Receiver Logic for Virtex-4 Devices

74

www.xilinx.com

Ethernet 1000BASE-X PCS/PMA or SGMII v9.1

 

 

UG155 March 24, 2008

Page 74
Image 74
Xilinx 1000BASE-X manual Idelay