CN8237EBGB Mindspeed Technologies, CN8237EBGB Datasheet - Page 92

• Manufacturer Part Number: CN8237EBGB
• Description: ATM SAR 622Mbps 3.3V ABR/CBR/GFR/UBR/VBR 456-Pin BGA
• Manufacturer: Mindspeed Technologies

Specifications of CN8237EBGB

• Package: 456BGA
• Traffic Class: ABR|CBR|GFR|UBR|VBR
• Utopia Type: Level 1|Level 2
• Host Interface: PCI
• Maximum Data Rate: 622 Mbps
• Typical Operating Supply Voltage: 3.3 V
• Minimum Operating Supply Voltage: 3.135 V

4.0 Segmentation Coprocessor
4.3 Segmentation Control and Data Structures
4-12
Table 4-3. Segmentation VCC Table Entry—AAL5 and 0 Field Descriptions (1 of 2)
PM_INDEX
ACK_PM
FWD_PM
LAST_PNTR
UU
PORT_ID
BOM_PNTR
ATM_HEADER
PDU_LEN
BUFFER_LEN
CRC_REM
STM_MODE
STAT
PM_EN
LAST_CLP
RUN
NX_EOM
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 call should be a 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 CN8237
inserts the UU field in the CPCS-PDU trailer contained in the EOM cell.
Identifies the Physical Device (Port) ID for the VCC.
In Message mode (STM_MODE=0), it points to the first buffer descriptor of a message composed of
more than one buffer descriptor. The CN8237 returns the corresponding USER_PNTR from this buffer
descriptor in the status queue.
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 data bytes read from the current segmentation buffer.
Accumulated value of AAL5 32-bit CRC, calculated on-the-fly by the SAR and appended to the PDU at EOM.
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.
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.
Flag that indicates that segmentation is proceeding. This flag is set to one by the SAR when the host
supplies data for the VCC; it is set to zero by the SAR when the data available for the VCC is not sufficient
to send at entire ATM cell.
Indicates that the next cell is the end of a CPCS-PDU.
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
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
ATM OC-12 ServiceSAR Plus with xBR Traffic Management
Chapter
Description
7.0.)
™
28237-DSH-001-C
CN8237