PXF4333 Datasheet, PDF (67/361 Pages) Infineon Technologies AG – ABM 3G ATM Buf fer Manager

Table 3-17 Threshold and Counter Table
Threshold
Related
Occupancy
Counter
Threshold Type
ABM-3G
PXF 4333 V1.1
Functional Description
TCT3
Enabling
Flags
Fixed
QueueLimit
(16383)
QueueLength
Maximum
PPD
1 x x x n x x 0/1
1 x 1 x n x x 0/1
TCT1 QueueMax
QueueLength
Maximum
64 0 x x y x x 0/1
PPD
64 0 1 x n x x 0/1
EPD
64 1 x x n x x 0/1
GFR
64 1 x 1 n x x 0/1
TCT0 QueueCiCLP1 QueueLength
CLP1
40 x x n 0 x 1
PPD
40 1 x n x x 1
EPD
41 x x n 1 x 1
QCT2 MinBG
QueueLength
Reservation
1, 8 x x x n x x 0/1
1) _{Not a true PPD threshold because the last cell of the packet is also discarded when BufMaxNg is exceeded.}
Note: The flags in columns “TCT3 enabling flags” indicate the traffic class settings
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.
Note: The thresholds and counters shown above are available in both the upstream and
the downstream ABM-3G core. In case of registers, the variable name is prefixed
with U for upstream and D for downstream in the register tables of Chapter 7.
3.4.1.6 Discard Mechanisms and Buffer Reservation
Each arriving cell is classified by determination of its QID, SBID, and TCID.
The discard mechanisms available in the ABM-3G Buffer Manager are based on
occupancy counters and the programmable thresholds described in Chapter 3.4.1.3
and Chapter 3.4.1.4.
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.
Data Sheet
67
2001-12-17