
XRT94L33
xr
Rev.1.2.0.
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
300
2.2.9.5.3
TRANSMISSION OF THE RDI-L INDICATOR
The Transmit STS-3 TOH Processor block provides the user with two options associated with transmitting the
Line-Remote Defect Indicator (RDI-L).
 Forced transmission of the RDI-L indicator (e.g., under Software control).
 Automatic transmission of the RDI-L indicator
Each of these options is discussed below.
2.2.9.5.3.1
Forced Transmission of the RDI-L Indicator (under Software Control)
The XRT94L33 permits the user to force the Transmit STS-3 TOH Processor block to transmit the RDI-L
indicator to the remote terminal equipment. The user can accomplish this by setting Bit 5 (RDI-L Force),
within the Transmit STS-3 Transport – SONET Transmit Control Register – Byte 0, to “1” as illustrated below.
Transmit STS-3 Transport – SONET Transmit Control Register – Byte 0 (Address = 0x1902)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
M0M1 Insert
Method[0]
Unused
RDI-L Force
AIS-L Force
LOS Force
Scramble
Enable
B2 Error
Insert
A1A2 Error
Insert
R/W
R/O
R/W
0
1
0
If the user opts to transmit an RDI-L indicator, then bits 6, 7 and 8 (of the K2 byte, within each outbound STS-
3c frame) will be set to the value [1, 1, 0].
Note:
This bit-field is ignored when either the “LOS Force” or the “AIS-L Force” bit-fields are set to “1”.
In this case, if the user wishes to terminate the Transmit STS-3c TOH Processor Block’s transmission of the
RDI-L indicator, then they only need to set Bit 5 back to “0”.
2.2.9.5.3.2
Automatic Transmission of the RDI-L (Line – Remote Defect Indicator)
The Transmit STS-3 TOH Processor block permits the user to configure it to automatically transmit the RDI-L
indicator, in response to the following conditions.
 The corresponding Receive STS-3 TOH Processor block declares an LOS (Loss of Signal) condition.
 The corresponding Receive STS-3 TOH Processor block is declaring an LOF (Loss of Frame) condition.
 The corresponding Receive STS-3 TOH Processor block is declaring the AIS-L condition.
Bits 0 through 2, within the Transmit STS-3 Transport – RDI-L Control Register, permits the user configure
the Transmit STS-3 TOH Processor block to support the “Automatic Transmission of an RDI-L indicator upon
detection of these conditions. These bit-fields are highlighted and defined below.