RS8234EBGC Mindspeed Technologies, RS8234EBGC Datasheet - Page 168

• Manufacturer Part Number: RS8234EBGC
• Description: RS8234EBGC ATM XBR SAR
• Manufacturer: Mindspeed Technologies

6.0 Traffic Management
6.2 xBR Cell Scheduler Functional Description
Figure 6-4. Schedule Slot Formats With USE_SCH_CTRL Not Asserted
6-8
6.2.2.3 Schedule Slot
VBR_OFFSET Described
NOTE(S):
(PRI=VBR_OFFSET+2)
Formats Without
USE_SCH_CTRL
VCC_Index
VCC_Index
VCC_Index
= User Defined
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 above, are illustrated in
assign 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), one from
the other. 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” (i.e., PRI = 5), then:
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
VBR_OFFSET = 5 – 3 = 2.
Mindspeed Technologies
illustrates how these priorities are assigned to the VBR fields.
ATM 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
(PRI=VBR_OFFSET+1)
(PRI=VBR_OFFSET+1)
(PRI=VBR_OFFSET+3)
VCC_Index
VCC_Index
VCC_Index
6-4. The SAR can
28234-DSH-001-B
VBR
VBR
VBR
RS8234
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