tdat04622 ETC-unknow, tdat04622 Datasheet - Page 110

• Manufacturer Part Number: tdat04622
• Description: Tdat Sonet/sdh 155/622/2488 Mbits/s Data Interfaces
• Manufacturer: ETC-unknow

TDAT042G5 SONET/SDH
155/622/2488 Mbits/s Data Interface
Functional Description
Data Engine (DE) Block
Over-Fiber Modes
In addition to the support of the normal SONET/SDH modes for different payload types such as HDLC, PPP, ATM
(X
for two payload types, SDL or ATM (X
the data stream contains no SONET/SDH overhead bytes.
In the over-fiber modes, it is possible to utilize the whole bandwidth (155 Mbits/s for OC-3, 622 Mbits/s for OC-12,
or 2.5 Gbits/s for OC-48) of the optical fiber for SDL packets or ATM cells.
As can be seen in Figure 21, for over-fiber modes the device is provisioned as follows:
I
I
I
I
82
43
The line termination (OHP) and path termination (PT) blocks of the device need to be provisioned in the
passthrough mode.
The payload termination (DE) block needs to be set to the bit synchronization mode in the payload control regis-
ter.
The transparent mode in the transmit and receive sequencers (addresses 0x102E and 0x102F; see register
description, page 223).
Bit 12 of the mode register (address 0x0010) needs to be set to 0 so that the received clock drives the entire
receive data path. In this way, there is no need to cross the clock domain boundary. As a result, only a single
channel is allowed for OC-3, OC-12, or OC-48 when the device is operated in the over-fiber modes. In contrast,
the device is capable of supporting four OC-3/OC-12 channels or one OC-8 channel in the SONET/SDH modes.
or X
31
), and SDL as shown in Figure 2 on pa ge45, this device is capable of supporting the over-fiber modes
SINGLE OC-48
SINGLE OC-12
SINGLE OC-3
Figure 21. TDAT042G5 Over-Fiber Modes: SDL, ATM (X
(continued)
TERMINATION
PASSTHROUGH
PASSTHROUGH
(continued)
LINE
31
). In the over-fiber mode, a 3% payload increase can be realized because
TERMINATION
PASSTHROUGH
PASSTHROUGH
µP INTERFACE
CONTROL
PATH
PACKET/CELL
PROCESSOR
-BIT SYNC
-DECAPSULATION
-UNSCRAMBLING
-CRC VERIFICATION
PACKET/CELL
PROCESSOR
-ENCAPSULATION
-SCRAMBLING
-CRC GENERATION
TERMINATION
PAYLOAD
31
)
ENHANCED
UTOPIA I/O
Agere Systems Inc.
Data Sheet
May 2001
5-6680(F).cr.1