RS8234EBGC Mindspeed Technologies, RS8234EBGC Datasheet - Page 101

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

Table 4-18. Segmentation Status Queue Entry
RS8234
ATM ServiceSAR Plus with xBR Traffic Management
4.3.5 Segmentation Status Queues
Table 4-19. Segmentation Status Queue Entry Field Descriptions
28234-DSH-001-B
Table 4-17. Transmit Queue Base Table Entry Field Descriptions
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
USER_PNTR
VLD
STOP
DONE
SINGLE
OVFL
I_EXP
I_MAN
SEG_VCC_INDEX
LOCAL
UPDATE
READ
0
1
4.3.5.2 Status Queue
4.3.5.1 Entry Format
Field Name
Field Name
Management
Copy of the USER_PNTR from the segmentation buffer descriptor. The SAR circulates this field from
the SBD without using it internally. In Message Mode, the SAR returns the USER_PNTR of the BOM
buffer. In Streaming Mode, the SAR returns the USER_PNTR of all buffers.
0 - Entry invalid. Indicates that the SAR has not written the entry and the host should halt status
processing.
1 - Entry valid. Indicates that the host may process the entry.
Written to one by the SAR. Written to zero by the host.
VCC has stopped because no more segmentation data is available.
Set when buffer segmentation is complete and buffer is released to host.
Set if SINGLE option is set in the segmentation buffer descriptor.
Overflow: status entry is last entry available. (See Status Queue Overflow, below.)
Current I_EXP rate parameter of the VCC. This field is written only when
VCC_INDEX(SCH_MODE) = ABR. (See
The two MSBs of the current I_MAN rate parameter for the VCC. This field is written only when
VCC_INDEX(SCH_MODE) = ABR. (See
Segmentation VCC index on which the SAR transmitted the buffer or PDU.
0 - READ_UD located in PCI address space.
1 - READ_UD located in SAR shared memory.
Note: For write-only PCI host interfaces, this bit should be set low.
SAR position in update interval. Number of queue entries processed since last update of READ_UD.
SAR read pointer. Represents the SAR’s current position in the transmit queue.
The RS8234 reports segmentation to the host on 1 of 32 status queues. Each entry
on the queue is two words.
entries.
At initialization, the host assigns the location and size of up to 32 queues by
initializing internal registers, the segmentation status queue base table entries.
I_EXP
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Rsvd
USER_PNTR
Table 4-18
Chapter
Chapter
Description
Description
6.0.)
6.0.)
and
™
4.3 Segmentation Control and Data Structures
Table 4-19
SEG_VCC_INDEX
4.0 Segmentation Coprocessor
describe the format of these
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