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Virtex-5 RocketIO GTP Transceiver User Guide
UG196 (v1.3) May 25, 2007
Chapter 6:
GTP Transmitter (TX)
R
TX Polarity Control
Overview
The GTP transceiver includes a TX polarity control function to invert outgoing data from
the PCS before serialization and transmission. The TXPOLARITY port is driven High to
invert the polarity of outgoing data.
Ports and Attributes
defines the TX polarity control ports.
There are no attributes in this section.
Description
The GTP transceiver can invert the polarity of its TX data before it is transmitted. This
feature can be used to avoid hardware fixes for swapped TXP/TXN differential traces on a
board.
Table 6-10:
TX Polarity Control Ports
Port
Dir
Clock
Domain
Description
TXPOLARITY0
TXPOLARITY1
In
TXUSRCLK2
Specifies if the final transmitter output is inverted
or not.
0
: Not inverted. TXP is positive, and TXN is
negative.
1
: Inverted: TXP is negative, and TXN is
positive.