pxf4336 Infineon Technologies Corporation, pxf4336 Datasheet - Page 72

• Manufacturer Part Number: pxf4336
• Description: Abm Premium Atm Buf Fer Manager
• Manufacturer: Infineon Technologies Corporation

Note: The flags in columns “TCT3 enabling flags” indicate the traffic class settings
Note: The thresholds and counters shown above are available in both the upstream and
3.4.1.6
Each arriving cell is classified by determination of its QID, SBID, and TCID.
The discard mechanisms available in the ABM-P Buffer Manager are based on
occupancy counters and the programmable thresholds described in
and
3.4.1.6.1 Maximum Fill Discard
A maximum fill discard occurs if the cell counter exceeds the related maximum fill
threshold at cell arrival.
The following maximum fill thresholds are available:
BufMax, and QueueLimit are determined by physical limits.
BufMaxNg, SBMax, TrafClassMax, QueueMax are configured per traffic class.
3.4.1.6.2 Selective CLP1 Discard
Selective discard is based on the CLP marking found in the arriving cells and is enabled
by the CLP transparency flag (CLPT) stored per connection in the LCI table.
In cell discard mode, the mechanism triggers tail drop for CLP=1 cells only. In this mode,
the mechanism is used to limit the buffer space provided for the non-guaranteed part of
VBR.2/.3 traffic.
In packet discard mode, the mechanism triggers EPD for CLP=1 frames only. According
to the GFR conformance definition, a CLP1 frame is assumed when the first cell of the
frame is a CLP1 cell. In this mode, the mechanism is used mainly for the GFR service.
The following discard thresholds are available to control selective CLP1 discard:
BufCiCLP1, SBCiCLP1, QueueCiCLP1.
Note: There is no selective CLP1 discard threshold available for the traffic class view.
Data Sheet
Chapter
required to make the threshold effective during cell acceptance algorithm for a cell
(connection) determined to belong to that traffic class. An ‘x’ means don’t care, i.e.
the flag has no effect on the threshold. The same applies to flag “CLPT” which is
a connection specific setting in the LCI table. The column “affected cells” indicates
whether the threshold affects CLP0, CLP1 or all cells.
the downstream ABM-P core. In case of registers, the variable name is prefixed
with U for upstream and D for downstream in the register tables of
Discard Mechanisms and Buffer Reservation
3.4.1.4.
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Functional Description
PXF 4336 V1.1
Chapter 3.4.1.3
Chapter
2001-12-17
ABM-P
7.