Table 59: RX Polarity Control Ports
Port
Dir
Clock Domain
Description
CH[0/1]_RXPOLARITY
In
CH[0/1]_RXUSRCLK2
The CH[0/1]_RXPOLARITY 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.
Notes:
1.
CH[0/1]_RXPOLARITY can be tied High if the polarity of RXP and RXN needs to be reversed.
RX Pattern Checker
The GTM receiver includes a built-in PRBS checker (see the following figure). This checker can be
set to check for one of the six industry-standard PRBS patterns. The checker is self-synchronizing
and works on the incoming data before comma alignment or decoding. This function can be used
to test the signal integrity of the channel.
Figure 43:
RX Pattern Checker Block
Polarity
Control
SIPO
Error
Counter
(32 bits)
PRBS-31 Pattern Checker
PRBS-23 Pattern Checker
PRBS-15 Pattern Checker
PRBS-9 Pattern Checker
RX_PRBS_ERR_CNT
CH[0/1]RXPRBSERR
CH[0/1]RXDATA
CH[0/1]RXPRBSPTN
PRBS-13 Pattern Checker
PRBS-7 Pattern Checker
Error
X20928-053118
Ports and Attributes
The following table defines the pattern checker ports.
Table 60: Pattern Checker Ports
Port
Dir
Clock Domain
Description
CH[0/1]_RXPRBSCSCNTRST
In
CH[0/1]_RXUSRCLK2
Reset the PRBS error counter.
Chapter 4: Receiver
UG581 (v1.0) January 4, 2019
Virtex Ult GTM Transceivers
101