CN8236EBGB Mindspeed Technologies, CN8236EBGB Datasheet - Page 93

• Manufacturer Part Number: CN8236EBGB
• Description: ATM SAR 155Mbps 3.3V ABR/CBR/GFR/UBR/VBR 388-Pin BGA
• Manufacturer: Mindspeed Technologies

Specifications of CN8236EBGB

• Package: 388BGA
• Traffic Class: ABR|CBR|GFR|UBR|VBR
• Utopia Type: Level 1|Level 2
• Host Interface: PCI
• Maximum Data Rate: 155 Mbps
• Typical Operating Supply Voltage: 3.3 V
• Minimum Operating Supply Voltage: 3 V

CN8236
ATM ServiceSAR Plus with xBR Traffic Management
28236-DSH-001-B
Table 4-6. Segmentation VCC Table Entry—AAL3/4, 5, and 0 Field Descriptions (1 of 2)
PM_INDEX
ACK_PM
FWD_PM
LAST_PNTR
UU
BOM_PNTR
ATM_HEADER
PDU_LEN
BUFFER_LEN
PORT_ID
CRC_REM
BETAG
SN
MID
STM_MODE
STAT/HPORT_ID
PM_EN
LAST_CLP
Field Name
Performance Monitoring index. 128 VCCs can be selected for automatic OAM PM generation. Each
monitored VCC has a unique performance monitoring index.
If this field is changed while the VCC is active, only the byte containing the field should be written.
(See
Toggled after each backward reporting PM cell is sent. Used to prevent PM information in PM table from
being overwritten before cell is sent.
Indicates that next cell should be forward monitoring PM cell.
Points to last buffer descriptor currently linked to the VCC. The two least significant bits of the pointer
are assumed to be 0 (word-aligned). The address of the buffer descriptor is (LAST_PNTR << 2) or
(LAST_PNTR x 4).
AAL5 User-to-User indication. This field is copied from the buffer descriptor UU field. The CN8236
inserts the UU field in the CPCS-PDU trailer contained in the EOM cell.
In Message mode (STM_MODE=0), points to the first buffer descriptor of a message composed of more
than one buffer descriptor. The CN8236 returns the corresponding USER_PNTR from this buffer
descriptor in the status queue.
In Streaming mode (STM_MODE=1), it is not used.
The two least significant bits of the pointer are assumed to be zero (word-aligned). The address of the
buffer descriptor is (BOM_PNTR<<2) or (BOM_PNTR * 4).
Used for each ATM cell for the VCC. The transmitted header may be modified by option bits in the
current buffer descriptor.
CPCS-PDU Trailer Length field. This field is generated by the SAR and inserted in the Length field of the
EOM cell.
Buffer Length. The number of bytes of data read from the current segmentation buffer.
Identifies the Physical Device (Port) ID for the VCC.
Accumulated value of AAL5 32-bit CRC, calculated on-the-fly by the SAR and appended to the PDU at EOM.
AAL3/4 Btag and Etag fields.
AAL3/4 Sequence Number field.
AAL3/4 Message Id field.
Streaming Status Mode.
0 = Message Mode—a status entry is written (with a corresponding maskable interrupt) only when the
1 = Streaming Mode—a status entry is written (with a corresponding maskable interrupt) for each buffer
Identifies the Segmentation Status Queue used for all status entries, or if the AALx_EN bit is set,
identifies the AALx port.
Enables performance monitoring for the VCC. If this bit is changed while the VCC is active, only the byte
containing the bit should be written. (See
Last transmitted CLP bit for VCC. This bit is updated by the SRC after each transmitted cell. This bit is in
the same word as the PM_EN bit, and is copied by the SAR from the current buffer descriptor. The bit is
used to select the correct VBR bucket for certain VBR VCCs.
last buffer in a message completes segmentation. The status entry written corresponds to the first
buffer descriptor in the message.
as it completes segmentation.
Chapter
6.0.)
Mindspeed Technologies
Chapter
Description
7.0.)
™
4.3 Segmentation Control and Data Structures
4.0 Segmentation Coprocessor
4-15