xrt94l33 Exar Corporation, xrt94l33 Datasheet - Page 149

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

xr
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
Setting this bit-field to “0” configures the XRT94L33 to operate in the ATM UNI Mode. Conversely, setting this
bit-field to “1” configures the XRT94L33 to operate in the PPP Mode.
Please refer to Section 4.0 for a description on how to configure the XRT94L33 to operate in the ATM UNI
Mode. Further, please refer to Section 5.0 for a description on how to configure the XRT94L33 to operate in
the PPP Mode.
2.0 ATM UNI MODE OPERATION
If the XRT94L33 (or a given channel within the XRT94L33) has been configured to operate in the ATM UNI
Mode, then the following functional blocks will become active.
• The Transmit UTOPIA Interface Block
• The Transmit ATM Cell Processor Block
• The Transmit STS-3c/SONET POH Processor Block
• The Transmit STS-3 TOH Processor Block
• The Receive STS-3 TOH Processor Block
• The Receive STS-3c/SONET POH Processor Block
• The Receive ATM Cell Processor Block
• The Receive UTOPIA Interface Block
Each of these functional blocks will be discussed in considerable detail, over the next few sections.
2.1
The user can configure a given channel within the XRT94L33 to operate in the ATM UNI Mode by setting Bit 2
(PPP/ATM*) within the Operation Control Register – Byte 0; to “0” as depicted below.
Operation Control Register – Byte 0 (Address = 0x0103)
Once the user executes this step, then the entire XRT94L33 will be configured to operate in the ATM UNI
Mode.
Tx UTOPIA
Clock De-
PLL OFF
Skew
B
R/W
IT
0
7
CONFIGURING THE XRT94L33 TO OPERATE IN THE ATM UNI MODE
Rx UTOPIA
Skew PLL
Clock De-
B
OFF
R/W
IT
0
6
RESYNC
Transmit
STS-3
B
R/W
IT
0
5
B
R/O
IT
0
4
Reserved
149
B
R/O
IT
0
3
ATM*
B
PPP/
R/W
IT
0
2
Reserved
B
R/W
IT
0
1
XRT94L33
Software
Reset
Rev.1.2.0.
B
R/W
IT
0
0