tdat04622 ETC-unknow, tdat04622 Datasheet - Page 111

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

Data Sheet
May 2001
Agere Systems Inc.
Functional Description
Data Engine (DE) Block
Transparent Payload Mode
The transparent payload mode in the payload termination data engine (DE) block is one of seven basic payload
type modes in the payload control registers and allows data to pass directly through the DE. In this mode, no fram-
ing is done on the data, and the data in the SONET frame is treated as raw data. The transparent payload mode
basically disables all the functions of the framers. In contrast, the transparent mode of the sequencer (over-fiber
mode) disables the conversion function of the sequencer between the SONET/SDH framing structure and the log-
ical channel structure.
In the transparent payload mode, the data engine processes the entire payload as a single packet with no J1 byte
or other POH. An RxSOP is generated on the UTOPIA interface on the first byte following the J1 byte. The last
byte of payload occurs at an RxEOP.
If the device is set in both the transparent payload mode in the payload control registers and the transparent mode
in the sequencer, then the whole SONET/SDH frame (overhead bytes will be overwritten with zeros) will appear at
the receive UTOPIA interface as one packet. At the transmit UTOPIA side, the whole SONET/SDH frame needs to
be supplied.
Transparent Receive Mode Control. In receiving from the line, provisioning must specify the time slot and
SONET frame byte location where the last byte in the packet will occur. The following registers are used to indicate
this location.
I
I
I
Transparent Transmit Mode Control. In transmitting to the line, provisioning must specify the time slot and
SONET frame alignment. This is done through Tx_TRANS_CTRL (address 0x102F; see register description,
page 223) used in conjunction with Tx_TS[1—12] (addresses 0x1016—0x1021; see register descriptions,
page 215).
In the case where the location of the last byte in the frame is not known, the last byte should be provisioned for
location 809 and time slot 12, and external UTOPIA hardware must perform packet delineation on the data
stream.
Rx_CHCD_FM (address 0x1030; see register description, page 224) specifies the time slot where the last byte
of a packet exists in channels C and D.
Rx_CHAB_FM (address 0x1031; see register description, page 224) specifies the time slot where the last byte
of a packet exists in channels A and B.
Rx_CELLA_FM (address 0x1032), Rx_CELLB_FM (address 0x1033), Rx_CELLC_FM (address 0x1034), and
Rx_CELLD_FM (address 0x1035) specify in which SONET location (0 to 809) the last byte in a packet exists in
channel A, B, C, or D, respectively. (See register descriptions, page 225.)
(continued)
(continued)
155/622/2488 Mbits/s Data Interface
TDAT042G5 SONET/SDH
83