S/UNI®-ATLAS-3200 Telecom Standard Product Data Sheet
Preliminary
The programming of the Configuration and OAM Configuration field in the VC Table determines
how the S/UNI-ATLAS-3200 will behave with respect to a particular connection.
Upon receipt of an OAM cell, the CRC-10 is checked. If the check sum is incorrect, the OAM
cell is not processed (i.e. alarms and counts are not updated) and the per-PHY errored OAM cell
count is incremented. If CRC10toUP is set in the Cell Processor Routing Configuration register,
bad-CRC OAM cells will be routed to the Microprocessor Cell interface. Otherwise, further
processing is dependent upon the contents of the OAM Type field and the programming of the
S/UNI-ATLAS-3200 for that connection.
If a connection is not provisioned as an end point (segment end-point or end-to-end point), all
incoming OAM cells (other than certain Loopback cells) are passed to the Output Cell Interface
(subject to policing, if so configured), regardless of whether or not the OAM Type or Function
Type fields have defined values. As an option, OAM cells may be discarded at non-flow end
points if the CRC-10 is incorrect. At flow end points, all OAM cells are terminated, except
Activate/Deactivate and Undefined OAM cells which may, optionally, be routed to the OCIF for
external processing.
10.9.1 Fault Management Cells
Fault Management cells are identified with an OAM Cell Type field of 0001. The S/UNI-
ATLAS-3200 supports segment and end-to-end AIS, RDI, Continuity Check (CC) and Loopback
cells.
Segment and End-to-End AIS alarm status bits in the Status field are set upon receipt of a single
AIS (function type = 0000) cell (segment or end-to-end). If the connection FM_Interrupt_Enable
bit is set, a globally maskable interrupt will be asserted at the change of state of the (segment or
end-to-end) AIS alarm. The alarm status is cleared upon receipt of a single user or CC cell, or if
no AIS cell has been received within the last 2.5 +/- 0.5 sec. If the AUTO_RDI VC table bit is
set, an RDI cell (segment or end-to-end) is generated immediately upon receipt of the first AIS
cell at a flow end point and once a second thereafter until the AIS state is exited. The S/UNI-
ATLAS-3200 generates RDI cells for insertion in the reverse flow and sends them to the
companion chip through the Backward Cell Interface. In addition, the S/UNI-ATLAS-3200 will
insert any RDI cells it receives over the backward cell interface into the cell stream it sources.
When the S/UNI-ATLAS-3200 receives a segment or end-to-end AIS cell, the Defect Location
and Defect Type fields of the AIS cell are copied into the VC Table. These fields are used when
RDI cells are generated at segment or end-to-end points as a result of the AUTO_RDI process.
Segment and End-to-End RDI alarm status bits are set upon receipt of a single RDI (function type
= 0001) cell (segment or end-to-end). The defect location and type fields will be copied into the
VC table for subsequent retrieval, so long as AIS alarm is not declared. While it is not reasonable
to expect the reception of both AIS and RDI of the same type (i.e. both segment or both end-to-
end), if this occurs the AIS defect location will be given priority for storage, so that it can be used
in the generation of RDI cells. If the connection FM_Interrupt_Enable bit is set, a globally
maskable interrupt will be asserted at the change of state of the (segment or end-to-end) RDI
alarm. The alarm status is cleared if no RDI cell has been received within the last 2.5 +/- 0.5 sec.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990553, Issue 4
105
PMC [ PMC-SIERRA, INC ]
