
CN8236
6.0 Traffic Management
ATM ServiceSAR Plus with xBR Traffic Management
6.5 Traffic Management Control and Status Structures
28236-DSH-001-A
Mindspeed Technologies
6-45
6.5.2.3 SCH_STATE
Fields For CBR
This section specifies the SCH_STATE portion (words 7 through 9) of the
Segmentation VCC table entry, when SCH_MODE = CBR.
The CBR SCH_STATE is shown in
Table 6-10, and the field descriptions are
Table 6-9. Schedule Slot Field Descriptions—CBR Traffic
Field Name
Description
CBR
Set high to indicate a CBR slot; set low to indicate a tunnel slot.
PRI3
Specifies the highest priority of four possible scheduling priority queues to service when a scheduling
slot for this CBR tunnel becomes active.
PRI2
Specifies the second highest priority of four possible scheduling priority queues to service when a
scheduling slot for this CBR tunnel becomes active.
PRI1
Specifies the third highest priority of four possible scheduling priority queues to service when a
scheduling slot for this CBR tunnel becomes active.
PRI0
Specifies the lowest priority of four possible scheduling priority queues to service when a scheduling
slot for this CBR tunnel becomes active.
CBR_VCC_INDEX
Segmentation VCC index for dedicated CBR schedule slot. CBR VCC indexes range from 0x0000 to
0x7FFE.
NOTE(S):
If the user wants only one priority of traffic scheduled in the CBR tunnel, assign the priority level to PRI3, and make
PRI2 the same priority. PRI1 and PRI0 values are Don’t Cares in this case. If two priorities are to be assigned to the tunnel,
assign the higher priority to PRI3 and the lower priority to PRI2, making PRI1 the same as PRI2. PRI0 is a Don’t Care in this
case. If three priorities are to be assigned to the tunnel, assigns the priorities by level to PRI3 (highest), PRI2 and PRI1 (lowest),
making PRI0 the same as PRI1. TUN_PRI0_OFFSET can be used to set PRI0 = PRI1, as needed.
Table 6-10. SCH_STATE for SCH_MODE = CBR
Word 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
7
Reserved
TUN_PRI_3
TUN_PRI_2
TUN_PRI_1
TUN_PRI_0
8
Reserved
9
Reserved
Table 6-11. CBR SCH_STATE Field Descriptions
Field Name
Description
TUN_PRI_3
When SCH_MODE is CBR and CBR_W_TUN bit is set to 1, this field specifies the highest priority of four
possible scheduling priority queues to service in place of the unused CBR slot. (This field is not active
when CBR_W_TUN = 0.)
TUN_PRI_2
When SCH_MODE is CBR and CBR_W_TUN bit is set to 1, this field specifies the second highest priority
of four possible scheduling priority queues to service in place of the unused CBR slot. (This field is not
active when CBR_W_TUN = 0.)
TUN_PRI_1
When SCH_MODE is CBR and CBR_W_TUN bit is set to 1, this field specifies the third highest priority of
four possible scheduling priority queues to service in place of the unused CBR slot. (This field is not
active when CBR_W_TUN = 0.)
TUN_PRI_0
When SCH_MODE is CBR and CBR_W_TUN bit is set to 1, this field specifies the lowest priority of four
possible scheduling priority queues to service in place of the unused CBR slot. (This field is not active
when CBR_W_TUN = 0.)