cn8236 Mindspeed Technologies, cn8236 Datasheet - Page 121

• Manufacturer Part Number: cn8236
• Description: Atm Servicesar Plus With Xbr Traffic Management
• Manufacturer: Mindspeed Technologies

CN8236
ATM ServiceSAR Plus with xBR Traffic Management
Figure 5-9. AAL5 Processing—CRC and PDU Length Checks
28236-DSH-001-B
. . .
5.3.1.3 AAL5 Error
ATM Cells
AAL5 PDU
Conditions
Accumulator
CRC-32
(User Data)
status queue entry for that channel. See
The user can set a global variable for the reassembly coprocessor, RSM_CTRL0
(MAX_LEN), dictating maximum SDU delivery length. The maximum allowable
length, in bytes, of any AAL5 CPCS-PDU, including trailer and pad, is
under reassembly does not exceed the maximum SDU delivery length.
The CN8236 reports this condition via a status queue entry, with the
LEN_ERROR and EPD status bits set. The AAL5_DSC_CNT counter is also
incremented. Refer to
Counter
Length
Figure 5-9
The CN8236 reports all PDU termination events, with or without errors, in a
During reassembly, this MAX_LEN value is checked to ensure that the PDU
If the CN8236 receives a non-EOM cell, where
Early Packet Discard is performed.
For each EOM cell where
the PDU is completed, with BA_ERROR status bit set.
EOM Cell
Mindspeed Technologies
PAD
illustrates these process functions.
UU
TOT_PDU_LEN
TOT_PDU_LEN
CPI LENGTH
min[RSM_CTRL0(MAX_LEN) 1024, 65568
Section
CRC-32
5.4.8, for details on how this process is handled.
+
+
48 > MAX_LEN
48 > MAX_LEN
(Compare)
(Not Null)
Section 5.6
Check)
™
(Pad
1024 (or 65568)
1024 (or 65568)
for full details.
5.0 Reassembly Coprocessor
5.3 CPCS-PDU Processing
Table Entry
RSM VCC
Queue
Status
Entry
8236_027
5-11