xrt94l33 Exar Corporation, xrt94l33 Datasheet - Page 292

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

XRT94L33
Rev.1.2.0.
2.2.8.3.11
Forcing Pointer Adjustments and NDF Events via Software
The “Transmit SONET POH Processor” block permits the user to insert pointer adjustments or NDF events
into the “outbound” STS-1 data stream. Specifically, the Transmit SONET POH Processor block permits the
user to implement the following “pointer-related” features.
• To force the pointer to shift to an “arbitrary value”
• To configure the Transmit SONET POH Processor block to only insert pointer-adjustment or NDF events, if
no pointer-adjustment (NDF or otherwise) events have occurred within the last three (3) STS-1 framing
periods.
• To force a “Positive-Stuff” pointer-adjustment event
• To force a “Negative-Stuff” pointer-adjustment event
• To force a Single NDF Event
• To force a Continuous NDF Event
• To read out and determine the current “pointer-value” within the outbound STS-1 data-stream.
The procedure for implementing each of these “pointer-related” events is presented below.
2.2.8.3.11.1
The Transmit SONET POH Processor block permits the user to assign the arbitrary value to the pointer bytes,
within the outbound STS-1 SPE data-stream. The user can invoke this feature by executing the following
steps.
STEP 1 – Write the appropriate “NDF”, “SS” and H1, H2 Pointer values into the “Transmit SONET Path
– Transmit Arbitrary H1 Pointer” register, and the “Transmit SONET Path – Transmit Arbitrary H2
Pointer” register.
The bit-format for these two registers is presented below.
Transmit SONET Path – Transmit Arbitrary H1 Byte Pointer Register (Address = 0xN9BF)
Transmit SONET Path – Transmit Arbitrary H2 Byte Pointer Register (Address = 0xN9C3)
B
B
R/W
R/W
IT
IT
0
0
7
7
POINTER-ADJUSTMENT/NDF OPTIONS
Forcing the Pointer to Shift to an Arbitrary Value
B
B
R/W
R/W
IT
IT
0
0
6
6
NDF Bits
B
B
R/W
R/W
IT
IT
0
0
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
5
5
H2 Pointer Value[7:0]
B
B
R/W
R/W
IT
IT
0
0
4
4
292
B
B
R/W
R/W
IT
IT
0
0
3
3
SS Bits
B
B
R/W
R/W
IT
IT
0
0
2
2
B
B
R/W
R/W
IT
H1 Pointer Value
IT
0
0
1
1
xr
B
B
R/W
R/W
IT
IT
0
0
0
0