XRT94L33
xr
Rev.1.2.0.
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
258
2.2.8.3
TRANSMISSION OF PATH-ALARM CONDITIONS
The Transmit SONET POH Processor block supports the following functions.
Transmitting the AIS-P Pattern (under Software control)
Transmitting the RDI-P Indicator (automatically and under Software control)
Transmitting the REI-P Indicator (automatically and under Software control)
Each of these operations is discussed in detail below.
2.2.8.3.1
TRANSMISSION OF THE AIS-P PATTERN
The Transmit SONET POH Processor block can be configured to generate and transmit the AIS-P (Path AIS)
indicator to the remote PTE, under software control.
The user can accomplish this by setting Bit 0 (Transmit AIS-P Enable) within the “Transmit SONET Path –
SONET Control Register – Byte 0” to “1”, as depicted below.
Transmit SONET Path – SONET Control Register – Byte 0 (Address = 0xN983)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
F2 Insertion
Type
REI-P Insertion Type[1:0]
RDI-P Insertion Type[1:0]
C2 Byte
Insertion
Type
Unused
Transmit
AIS-P
Enable
R/W
R/O
R/W
0
1
Once the user executes this step, then the “Transmit SONET POH Processor” block will do the following.
It will set all bytes, within the STS-1 SPE to an “All Ones” pattern.
It will set the H1, H2 and H3 bytes (within the TOH) to an “All Ones” pattern.
Please note that whenever the user configures the Transmit SONET POH Processor block to transmit the
AIS-P indicator, then no ATM cells or PPP packets will be transmitted to the remote terminal.
2.2.8.3.2
TRANSMISSION OF THE RDI-P INDICATOR
The Transmit SONET POH Processor block can be configured to transmit the RDI-P indicator either
automatically, upon software control or via the “TxPOH_n” external input port as described below.
2.2.8.3.2.1
Configuring the Transmit SONET POH Processor block to automatically transmit the
RDI-P Indicator
The user can configure the Transmit SONET POH Processor block to automatically transmit the RDI-P
indicator whenever the corresponding Receive SONET POH Processor block declares a PLM-P (Path –
Payload Label Mismatch), UNEQ-P (Path – Unequipped), LOP-P (Path – Loss of Pointer), AIS-P, TIM-P
(Path - Trace Identification Mismatch), and LCD-P (Path – Loss of Cell Delineation) condition.
The procedure for configuring the Transmit SONET POH Processor block to automatically transmit the RDI-P
indicator, for each of the above-mentioned defects is presented below.
2.2.8.3.2.2
Configuring the Transmit SONET POH Processor block to automatically transmit RDI-
P, in response to declaration of the PLM-P Condition
The user can configure the Transmit SONET POH Processor block to automatically transmit the RDI-P
indicator, in response to the corresponding Receive SONET POH Processor block declaring the PLM-P
condition, by executing the following steps.