GS6152 Datasheet, PDF (44/80 Pages) Semtech Corporation – Multi-Rate 6G UHD-SDI

are used to operate the Input PRBS checker (and in fact Input PRBS checking is
automatically performed by the device when an Arbitrary Data eye scan or error check
is performed) the user is referred to the previous section for details on programming the
HEM. PRBS-specific registers which are additionally set or observed and their Arbitrary
Data equivalents are given in Table 4-9 below.
Table 4-9: Arbitrary Data Checker Registers and Equivalent Input PRBS7 Checker Registers
Arbitrary Data Checker
Input PRBS7 Checker
Register
Parameter
Does Not Apply
EYE_MON_CONTROL_REG_4
ERROR_THRESHOLD
EYE_MON_CONTROL_REG_6
EYE_MON_CONTROL_REG_6
EYE_MON_CONTROL_REG_6
EYE_MON_WINDOW
EYE_MON_FORCE_CLEAR
EYE_MON_CLEAR
EYE_MON_STATUS_REG_2
STARTING_PHASE
EYE_MON_STATUS_REG_2
EYE_WIDTH
EYE_MON_STATUS_REG_2
ERROR_COUNT
Does Not Apply
Register
Parameter
EYE_MON_ENABLE
EYE_MON_PRBS_NODATA_SET
EYE_MON_CONTROL_REG_3
EYE_MON_PRBS_ERROR_
THRESHOLD
Does Not Apply
EYE_MON_CONTROL_REG_6 EYE_MON_PRBS_FORCE_CLEAR
EYE_MON_CONTROL_REG_6
EYE_MON_PRBS_CLEAR
EYE_MON_STATUS_REG_0
EYE_MON_PRBS_STARTING_
PHASE
EYE_MON_STATUS_REG_0
EYE_MON_PRBS_EYE_WIDTH
EYE_MON_STATUS_REG_1 EYE_MON_PRBS_ERROR_COUNT
EYE_MON_STATUS_REG_12
EYE_MON_PRBS_NODATA
The eye bitmap registers in EYE_MON_STATUS_REG_4… EYE_MON_STATUS_REG_11
can be set to provide the bitmap when the PRBS checker is used as the criteria for bit
errors when the EYE_MON_SELECT bit is set to 0 (PRBS7 bit stream).
Due to the nature of the PRBS polynomial an input without data transitions may be
detected as error-free. To circumvent this possibility the EYE_MON_PRBS_NODATA bit
of the EYE_MON_STATUS_REG_12 register indicates if no data transitions have been
detected if the bit remains high after the EYE_MON_PRBS_NODATA_SET bit of the
EYE_MON_ENABLE register has been toggled high, then low.
4.12.2.2 Re-timed Data PRBS Checker
The re-timed bit stream is checked using a separate PRBS checker which is controlled
and checked with separate registers from either the arbitrary eye monitor or Input
PRBS7 checker and is enabled by setting the PRBS_MON_ENABLE bit of the
PRBS_CHK_CTRL register and controlled with registers PRBS_CTRL_0 …, PRBS_CTRL_8.
The results are stored in PRBS_STATUS_REG_0 and PRBS_STATUS_REG_1. The operation
of the Re-timed Data PRBS checker is very similar to the Arbitrary Data HEM and Input
PRBS checker and the user is referred to the previous sections for equivalent registers
are given in Table 4-10 below.
GS6152
Final Data Sheet
PDS-060984
Rev.2
July 2015
www.semtech.com
44 of 80
Semtech
Proprietary & Confidential