Table 60: Pattern Checker Ports (cont'd)
Port
Dir
Clock Domain
Description
CH[0/1]_RXPRBSPTN[3:0]
In
CH0_TXUSRCLK2
Receiver PRBS checker test pattern
control. Only these settings are valid:
4’b0000
: Standard operation
mode (PRBS check is off)
4’b0001
: PRBS-7
4’b0010
: PRBS-9
4’b0011
: PRBS-15
4’b0100
: PRBS-23
4’b0101
: PRBS-31
4’b0110
: PRBS-13
After changing patterns, perform a
reset of the RX or a reset of the PRBS
error counter
(CH[0/1]_RXPRBSCSCNTRST) such that
the RX pattern checker can attempt to
reestablish the link acquired. No
checking is done for non-PRBS
patterns.
CH[0/1]_RXPRBSERR
Out
CH[0/1]_RXUSRCLK2
This non-sticky status output indicates
that PRBS errors have occurred. Only
use CH[0/1]_RX_PRBSERR to read the
precise bit error counts.
CH[0/1]_RXPRBSLOCKED
Out
CH[0/1]_RXUSRCLK2
Output to indicate that the RX PRBS
checker has been error free for
CH[0/1]_RX_PCS_CFG1[12:5] cycles after
reset. After being asserted High,
CH[0/1]_RXPRBSLOCKED does not
deassert until reset of the RX pattern
checker via a reset of the RX
(GTRXRESET, RXPMARESET, or
RXPCSRESET in sequential mode) or a
reset of the PRBS error counter
(CH[0/1]_RXPRBSCSCNTRST).
CH[0/1]_RXPRBSCNTSTOP
In
CH[0/1]_RXUSRCLK2
Input control to stop the error counter.
The PRBS checker needs to restart the
error counter after a PRBS stop.
The following table defines the pattern checker attributes.
Table 61: Pattern Checker Attributes
Attribute
Type
Description
CH[0/1]_TX_PCS_CFG1
16-bit
Reserved.
Bit Name
Address
Description
RXPRBSERR_LOOPBACK
[7]
When this attribute is set to 1, the CH[0/1]_RXPRBSERR bit is
internally looped back to CH[0/1]_TXPRBSINERR of the same GTM
transceiver. This allows synchronous and asynchronous jitter
tolerance testing without worrying about data clock domain
crossing. When this attribute is set to
1b’0
, CH[0/1]_TXPRBSINERR
is forced onto the TX PRBS.
Chapter 4: Receiver
UG581 (v1.0) January 4, 2019
Virtex Ult GTM Transceivers
102