XRT94L33
xr
Rev.1.2.0.
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
296
2.2.9
TRANSMIT STS-3 TOH PROCESSOR BLOCK
The purpose of the Transmit STS-3 TOH Processor Block is to accomplish the following.
To accept STS-3c SPE data from the Transmit STS-3c POH Processor Block (for STS-3c Applications)
To accept 3 channels of STS-1 SPE data from each of the three (3) Transmit SONET POH Processor
blocks (for STS-3 Applications)
To compute and insert the B1 (Section BIP-8) and B2 (Line BIP-8) bytes.
To source the K1/K2, E1, M0, J0, F1 and S1 bytes.
To transmit the RDI-L (Line – Remote Defect Indicator) Indicator.
To transmit the REI-L (Line – Remote Error Indicator) Indicator.
To transmit the AIS-L (Line – Alarm Indication Signal) Indicator
To deliberately transmit an erred B1 or B2 byte (for testing purposes)
To optionally scramble the outbound STS-3 data.
To output this data to either the Transmit PECL Interface or the Transmit STS-3 Telecom Bus Interface, for
transmission to the remote terminal equipment.
Figure 57 presents an illustration of the Functional Block Diagram of the XRT94L33 ATM UNI/PPP/Mapper IC
Figure 57: Illustration of the Functional Block Diagram of the XRT94L33 ATM UNI/PPP/Mapper IC with
the Transmit STS-3 TOH Processor Block highlighted
Transmit
UTOPIA
Interface
Block
Transmit
UTOPIA
Interface
Block
Receive
UTOPIA/
Interface
Block
Receive
UTOPIA/
Interface
Block
Transmit
ATM
Cell Processor
Block
Transmit
ATM
Cell Processor
Block
Receive
ATM
Cell Processor
Block
Receive
ATM
Cell Processor
Block
Transmit
PPP
Processor
Block
Transmit
PPP
Processor
Block
Receive
PPP
Processor
Block
Receive
PPP
Processor
Block
Receive
STS-3/12
TOH
Processor
Block
Receive
STS-3/12
TOH
Processor
Block
Transmit
STS-3/12
TOH
Processor
Block
Transmit
STS-3/12
TOH
Processor
Block
Receive
STS-3/12
POH
Processor
Block
Receive
STS-3/12
POH
Processor
Block
Transmit
STS-3/12
POH
Processor
Block
Transmit
STS-3/12
POH
Processor
Block
STS-3/12
Telecom
Bus
Interface
Block
STS-3/12
Telecom
Bus
Interface
Block
STS-3/12
PECL
Interface
Block
STS-3/12
PECL
Interface
Block
STS-3/12
CDR
Block
STS-3/12
CDR
Block
XRT95L34 – Channel 0
Transmit
POS-PHY
Interface
Block
Transmit
POS-PHY
Interface
Block
Receive
POS-PHY
Interface
Block
Receive
POS-PHY
Interface
Block
Clock
Synthesizer
Block
Clock
Synthesizer
Block
Microprocessor
Interface
Block
Microprocessor
Interface
Block
SOME BACKGROUND INFORMATION ON THE TRANSPORT OVERHEAD (TOH) BYTES
As mentioned earlier, the XRT94L33 will handle either STS-1 frame, STS-3c frames, or STS-3. The size of
an STS-3 frame is 9 rows by 270 byte columns.
Figure 58 presents a simple illustration of the STS-3 Frame.