VSC6134
Datasheet
2.9.5.12
2.9.5.13
OPUk Justification Bytes
There is no on-chip monitoring of the OPUk justification bytes
Framed PRBS Monitor
The framed PRBS monitor sets the FPRBSSYNCL live bit when it locks to one of several PRBS
sequences in the OTUk payload. A change in the live bit status sets the status bit FPRBSSYNCS and the
status bit, together with its mask bit FPRBSSYNCM, create a maskable hardware interrupt.
The choices for monitored PRBS sequences are
14
15
●
●
●
●
1 + x + x
3
20
1 + x + x
18
23
31
1 + x + x
28
1 + x + x
The framed PRBS monitor excludes the stuff bytes in the OTUk payload when FPRBSCONFIG is low
and includes the stuff bytes when high. FPRBSSELECT selects one of the four sequences and
FPRBSINVERT inverts the sequence.
FPRBSENABLE turns on the monitor. When it is in lock, the monitor never goes out of lock until it is
disabled, and it records any deviations from the selected PRBS sequence as bit errors in
FPRBSERRCNT[31:0]. A bit error sets the status bit FPRBSERRS and, together with its mask bit
FPRBSERRM, creates a maskable hardware interrupt.
2.9.5.14
Generic AIS Monitor
Generic AIS is monitored over the payload of the OTUk frame. When OTUk_GAIS_CFG = 0, generic
AIS monitoring is done over the payload excluding the stuff bytes. When OTUk_GAIS_CFG = 1,
generic AIS monitoring is done over the payload including the stuff bytes.
The live bit OTUk_GAISL sets when the monitor detects generic AIS. Each live bit transition sets the
status bit OTUk_GAISS. The status bit and its respective mask bit OTUk_GAISM create a maskable
hardware interrupt.
2.9.5.15
2.9.5.16
OTUk AIS Monitor
OTUk AIS is an unframed PRBS sequence. The OTUk AIS monitor sets the live bit OTUk_AISL when
it detects OTUk AIS. Each live bit transition sets the status bit OTUk_AISS. The status bit and its
respective mask bit OTUk_AISM create a maskable hardware interrupt.
BDI Transmission to the DW Overhead Generator
OTUk_BDISF[1:0] determine which combination of LOS and LOF set the BDI signal automatically
(OTUk_BDI_MANU = 0). The overhead monitor passes the BDI signal to the overhead generator for
insertion as OTUk_SMBDI, OTUk_TCMBDI and OTUk_PMBDI in the backwards direction (see the
following table).
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VMDS-10185 Revision 4.0
July 2006
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
