pxf4336 Infineon Technologies Corporation, pxf4336 Datasheet - Page 75

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

Figure 3-18 Buffer Management with per Queue Minimum Buffer Reservation
For all traffic classes, the threshold BufMaxNg must be adjusted appropriately, such that,
if LQ is the set of logical queues allocated so far, then:
Although the ABM-P in principle has the knowledge of all programmed guaranteed
minimum queue sizes, it does not perform the summation for complexity reasons.
Refer to
reservation thresholds. If the condition in the formula above is not fulfilled, then error
condition BCFGE occurs and is signalled in
Register 116 "ISRD" on Page 359
3.4.1.6.5 Hysteresis for Maximum Thresholds
Hysteresis is an optional feature for the maximum thresholds BufMaxNg, SBMax,
TrafClassMax, and QueueMax in cell discard mode. Hysteresis means that cell discard
starts when any of the maximum thresholds mentioned above (referred to as TH for
convenience) is exceeded and continues until the level falls below a threshold TL that is
considerably lower than TH.
A hysteresis control parameter DH
the low threshold TL
Data Sheet
BufMax BufMaxNg
BufMax
BufMaxNg
BufEPD
BufferOccNg
–
Register 45 "QCT2" on Page 264
queues / connections
Reserved queue 1
Reserved queue 2
Reserved queue 3
i
≥
from a given high threshold TH
Part of Buffer
shared by all
∀
i
å
∈
LQ
MinBG
i
is provided per traffic class i. It is used to calculate
respectively.
i
QueueLimit
75
for the programming of minimum buffer
QueueMax
Register 115 "ISRU" on Page 356
Shared buffer
i
according to:
MinBG
Reserved buffer
QueueLength
Functional Description
PXF 4336 V1.1
Queue 1
Queue 2
Queue 3
2001-12-17
ABM-P
or