Rx Polarity Control; Functional Description; Ports And Attributes; Using Rx Polarity Control - Xilinx Virtex-6 FPGA User Manual

Table 4-27
Table 4-27: RX Margin Analysis Attributes
Attribute
RX_EYE_OFFSET
RX_EYE_SCANMODE

RX Polarity Control

Functional Description

The GTX RX can invert incoming data using the RX polarity control function. This function
is useful in designs where the RXP and RXN signals can be accidentally connected in
reverse. The RXPOLARITY port is driven High to invert the polarity of incoming data.

Ports and Attributes

Table 4-28
Table 4-28: RX Polarity Control Ports
There are no RX polarity control attributes.

Using RX Polarity Control

If the polarity of RXP/RXN needs to be inverted, RXPOLARITY must be tied High.
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Virtex-6 FPGA GTX Transceivers User Guide
UG366 (v2.5) January 17, 2011
defines the RX margin analysis attributes.
Type
8-bit When RX_EYE_SCANMODE = 10 or 01, RX_EYE_OFFSET determines the offset
Hex between the edge sampler, controlled by the CDR, and the data sampler. The valid
range is 0 to 127 (0x00 to 0x7F) which corresponds to the 0 to 1.0 UI position of a
serial data bit.
2-bit RX_EYE_SCANMODE determines if the receiver should work in normal operation
Binary of in the scan operation.
00: Regular data operation. RX_EYE_OFFSET is ignored.
01: Eye outline scan mode.
10: Horizontal eye margin scan mode.
11: Reserved.
defines the RX polarity control ports.
Port Dir Clock Domain
RXPOLARITY In RXUSRCLK2
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Description
Description
The RX polarity port can invert the polarity of
incoming data.
0: Not inverted. RXP is positive and RXN is
negative.
1: Inverted. RXP is negative and RXN is
positive.
RX Polarity Control
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