S/UNI®-ATLAS-3200 Telecom Standard Product Data Sheet
Preliminary
7
Description
The PM7325 S/UNI®-ATLAS-3200 device is a monolithic integrated circuit that implements the
ATM Layer functions that include fault and performance management, header translation and cell
rate policing. The S/UNI-ATLAS-3200 device is a uni-directional part that is intended to reside
between the physical layer (PHY) devices and a traffic manager in the ingress side, and a traffic
shaper and the PHY devices in the egress side. The S/UNI-ATLAS-3200 supports a sustained
aggregate throughput of 5.68x106 cells/s in each of the Ingress and Egress modes. The S/UNI-
ATLAS-3200 uses external SRAM to store the search tree data structures. The device is capable
of supporting up to 64K connections. Apart from the operation of the UL3 or POS-PHY™ Level
3 interfaces, the S/UNI-ATLAS-3200 is fully symmetric, with identical features and configuration
options in either direction.
The Input Cell Interface can be connected to a PHY device supporting up to 48 PHY queues via a
UTOPIA Level 3 or POS-PHY Level 3 bus, or may emulate up to 48 PHYs via multi-PHY
addressing over a UTOPIA Level 3 or POS-PHY Level 3 bus. The 52- or 53-byte ATM cell is
encapsulated in a data structure that can contain prepended or postpended routing information,
and can fill the HEC field out to 32 bits. Received cells are buffered in a programmable-depth
per-PHY FIFO. All idle cells, physical layer and unassigned cells are discarded, and any cells
from PHY queues designated as packet PHYs are routed to the output untouched. For the
remaining cells, a subset of ATM header and appended bits is used as a search key to find the VC
Table record for the virtual connection. If a connection is not provisioned and the search
terminates unsuccessfully as a result, the cell is discarded and a count of invalid cells is
incremented. If the search is successful, subsequent processing of the cell is dependent on the
contents of the cell and configuration fields in the VC Table Record.
The S/UNI-ATLAS-3200 performs header translation, if so configured. The ATM header is
replaced by the contents of fields in the VC Table Record for that connection. The VCI contents
are passed through transparently for VPC connections; the PTI is passed through transparently for
all connections. The CLP bit may only be altered via the policing function. Appended bytes can
be replaced, added or removed.
If the S/UNI-ATLAS-3200 is the end point for a F4 or F5 OAM flow, the OAM cells are
terminated and processed. If the S/UNI-ATLAS-3200 is not the end point, the OAM cells are
passed to the Output Cell Interface with an optional copy passed to the Microprocessor Cell
Interface FIFO. The reception of AIS or RDI cells results in the appropriate alarms (segment or
end-to-end alarm). Interrupts corresponding to the alarm bits can be masked on a per-connection
basis. When configured as a sink of PM cells, upon the arrival of a Forward Monitoring cell,
error counts are updated and a Backward Reporting cell is optionally generated and routed to the
Backwards Cell Interface that is connected to the opposite-direction S/UNI-ATLAS-3200. When
configured as a source of PM cells, the S/UNI-ATLAS-3200 generates a Forward Monitoring cell
when the per-session programmable user cell block size is reached. The insertion of PM cells is
paced so that bursts of generated cells will not cause a backup.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990553, Issue 4
35
PMC [ PMC-SIERRA, INC ]
