cn8237 Mindspeed Technologies, cn8237 Datasheet - Page 166

• Manufacturer Part Number: cn8237
• Description: Atm Oc-12 Servicesar Plus With Xbr Traffic Management
• Manufacturer: Mindspeed Technologies

6.0 Traffic Management
6.2 xBR Cell Scheduler Functional Description
Figure 6-4. Schedule Slot Formats without USE_SCH_CTRL Asserted
6-10
6.2.2.3 Schedule Slot
NOTE(S):
VBR_OFFSET Described
(PRI=VBR_OFFSET+2)
Formats without
USE_SCH_CTRL
= User Defined
VCC_Index
VCC_Index
VCC_Index
CBR_TUN = 1, DBL_SLOT = 0
CBR_TUN = 1, DBL_SLOT = 1
CBR
CBR
VBR
Asserted
(PRI=VBR_OFFSET+1)
(PRI=VBR_OFFSET+1)
(PRI=VBR_OFFSET+3)
the last four rows of the table, are illustrated in
VBR VCC index(es) to any or all of the VBR VCC_Index fields in a schedule
table slot. Each of the VBR fields in a schedule table slot that are assigned a VBR
VCC_Index have a different scheduling priority (PRI). Also, any of these VBR
VCC_Indexes assigned by the SAR can be the first of a linked list of VBR VCCs.
user or system designer wishes to assign VBR channels and what the SAR assigns
via the VBR Schedule Slot format. Thus, the value of VBR_OFFSET is the
difference between the highest VBR/ABR priority being actively scheduled and
the largest priority of the VBR VCC_Index field in the VBR scheduling slot
(either one or three). For example, if the system designer assigns VBR/ABR
VCCs to three different scheduling priorities with the highest of those priorities
being 5 (that is, PRI = 5), then VBR_OFFSET = 5 – 3 = 2.
VCC_Index
VCC_Index
VCC_Index
The VCC index contents of each Schedule table slot, based on the settings in
VBR_OFFSET gives the offset difference in priority level between what the
Figure 6-4
VBR
VBR
VBR
Mindspeed Technologies
illustrates how these priorities are assigned to the VBR fields.
ATM OC-12 ServiceSAR Plus with xBR Traffic Management
(PRI=VBR_OFFSET+0)
(PRI=VBR_OFFSET+0)
(PRI=VBR_OFFSET+2)
VCC_Index
VCC_Index
VCC_Index
™
CBR_TUN = 0, DBL_SLOT = 0
CBR_TUN = 0, DBL_SLOT = 1
VBR
VBR
VBR
Figure
6-4. The SAR can assign
(PRI=VBR_OFFSET+1)
(PRI=VBR_OFFSET+1)
(PRI=VBR_OFFSET+3)
VCC_Index
VCC_Index
VCC_Index
28237-DSH-001-C
VBR
VBR
VBR
CN8237
8237_059