
Agere Systems Inc.
61
Data Sheet
May 2001
155/622/2488 Mbits/s Data Interface
TDAT042G5 SONET/SDH
Functional Description
(continued)
Overhead Processor (OHP) Block
(continued)
Transmit OHP
(continued)
BIP-8 Generation.
The SBIP block calculates the B1 value according to Bellcore and ITU standards. Insertion of
SBIP errors is possible through the use of software control register TB1ERRINS[A
—
D] (see register description,
page 180).
The LBIP block calculates the B2 values according to Bellcore and ITU standards. Insertion of LBIP errors is pos-
sible through the use of software control register TB2ERRINS[A
—
D] (see register description, page 180).
The REI_L block controls the insertion of the remote error indication block error count.
J0 Section Trace.
The section trace message is inserted either from the TxTOH interface or from a message
stored in a 16-byte software-accessible memory. Control for message insertion is from software control register
TJ0INS[A
—
D] (see register description, page 177 and page 181).
SONET Scrambler.
The scrambler block implements the frame synchronous SONET scrambler with a generating
polynomial of 1 + x
6
+ x
7
. The scrambler may be disabled through a software register.
A1/A2 Framing Bytes.
A1 and A2 are automatically placed on the line. Errors can be inserted into A2 by setting
OHP register TA1A2ERRINS[A
—
D][4:0] (see register description, page 180).
E1/E2 Orderwire Bytes.
The orderwire bytes for section and line are taken from the TOAC.
D1/D2/D3 Section Data Communications Channels (DCC).
DCC inputs are taken from the TOAC.
D4
—
D12 Line Data Communications Channels (DCC).
DCC inputs are taken from the TOAC.
F1 User Channel.
The F1 byte can be optionally inserted from stored values in OHP register TF1INS[A
—
D]
(addresses 0x047E, 0x0480, 0x0482, 0x0484; see register description, page 179 and page 183).
M1 REI-L.
REI-L can be automatically generated and inserted into the outgoing SONET frame, or can optionally
be inhibited. Errors can be inserted into M1 via OHP register TM1_ERR_INS[A
—
D] (addresses 0x042E, 0x0430,
0x0432, 0x0434; see register description, page 179 and page 183).
Support for ATM/Packet-Over-Fiber.
The transport overhead must be bypassed when operating in data-over-
fiber mode. In this mode, the TOH_BYPASS and ROH_BYPASS register bits must be set to 1. No overhead inser-
tion/extraction is done when in bypass mode.