xrt94l33 Exar Corporation, xrt94l33 Datasheet - Page 181

• Manufacturer Part Number: xrt94l33
• Description: Multi-channel, Multi-function Device Aggregates 3 Ds3/e3/sts-1 Into Oc3/stm-1
• Manufacturer: Exar Corporation

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3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
2.2.6.1
The Transmit ATM Cell Processor block permits the user to either enable or disable each of the four Transmit
User Cell Filters. The user can accomplish this by writing the appropriate data into Bit 3 (User Cell Filter
Enable), within the “Transmit ATM Filter Control – Byte 0” register; as depicted below.
Transmit ATM Filter # 0, # 1, # 2, # 3 Control – Byte 0 (Address = 0xNF43, 0xNF53, 0xNF63, 0xNF73)
Note:
Setting this bit-field to “1” enables the corresponding Transmit User Cell Filter. Conversely, setting this bit-
field to “0” disables the “Transmit User Cell Filter”.
If a given Transmit User Cell Filter is enabled, then it will perform action on all incoming ATM cells, based
upon the settings of the remaining register bits within this register; and that within both the “Transmit ATM
Filter Control – Pattern” and “Transmit ATM Filter Control – Check” registers. Conversely, if the given
Transmit User Cell Filter is disabled, then all User Cells will pass through the Transmit User Cell Filter, and
towards the “HEC Byte Calculation & Insertion” block without any such actions performed on these cells.
2.2.6.2
The Transmit ATM Cell Processor block permits the user to specify the action that the User Cell Filter will take
on each cell, that meets certain “User-Defined” Filtering requirements. The user can accomplish this by
setting Bits 2 (Copy Cell Enable) and 1 (Discard Cell Enable), within the Transmit ATM Filter Control – Byte 0”
Register; to the appropriate values. These two bit-fields are highlighted below.
Transmit ATM Filter # 0, # 1, # 2, # 3 Control – Byte 0 (Address = 0xNF43, 0xNF53, 0xNF63, 0xNF73)
Bit 2 – Copy Cell Enable
This bit-field permits the user to configure the “Transmit User Cell” filter (within the Transmit ATM Cell
Processor block) to either replicate (copy) or not replicate a given cell that complies with the “user-defined”
filtering requirements. All copied cells are routed to the “Transmit ATM Cell Processor Extraction Memory”,
where their contents can be read out by the user via the Microprocessor Interface.
Setting this bit-field to “1” configures the Transmit User Cell Filter to copy all cells that comply with the “user-
cell” filter requirements, and to route these cells to the “Transmit ATM Cell Processor – Extraction Memory”.
Conversely, setting this bit-field to “0” configures the Transmit User Cell Filter to NOT copy these cells, and
NOT route these cells to the “Transmit ATM Cell Processor – Extraction Memory.
B
B
R/O
R/O
IT
IT
0
0
7
7
As the bit-format table for the “Transmit ATM Filter Control – Byte 0” register implies, each of the four (4)
Transmit User Cell Filters can be individually enabled or disabled. Further, each of these four Transmit User
Cell Filters can be individually configured to either “Copy” or “Discard” cells (or both).
E
S
NABLING
ELECTING THE
B
B
R/O
R/O
IT
IT
0
0
6
6
/D
Unused
Unused
ISABLING THE
T
RANSMIT
B
B
R/O
R/O
IT
IT
0
0
5
5
T
U
RANSMIT
SER
C
ELL
B
B
R/O
R/O
IT
IT
0
0
U
4
F
4
SER
ILTER
181
C
ELL
A
Filter Enable
Filter Enable
User Cell
CTION
User Cell
F
B
B
R/W
R/W
ILTER
IT
IT
X
1
3
3
Copy Cell
Copy Cell
Enable
Enable
B
B
R/W
R/W
IT
IT
0
X
2
2
Discard
Discard
Enable
B
B
R/W
R/W
Cell
Cell
IT
IT
X
0
1
1
XRT94L33
Filter Sense
Filter Sense
User Cell
User Cell
Rev.1.2.0.
B
B
R/W
R/W
IT
IT
0
X
0
0