TXC-04222-AIOG Transwitch Corporation, TXC-04222-AIOG Datasheet - Page 87

• Manufacturer Part Number: TXC-04222-AIOG
• Manufacturer: Transwitch Corporation

Specifications of TXC-04222-AIOG

• Screening Level: Industrial
• Package Type: BGA
• Lead Free Status / Rohs Status: Not Compliant

Line loopback enables the received DS1 or E1 data and clock signals to be looped back as transmit signals.
The DS1 or E1 line signals at the input are disabled. The VT/TU are demapped and mapped according to the
VT/TU selection registers. When control bit RnLAIS (bit 0, X+000H) is a 1, line AIS is outputted for the receive
rail or NRZ interface while the receive data for the VT/TU is simultaneously looped back. When RnLAIS is set
to 0, the receive data for the VT/TU is outputted in addition to being looped back. RnLAIS is enabled only when
line loopback is enabled. The RnCLKI (bit 3, register X+000H) and TnCLKI (bit 3, register X+002H) control bits
must be programmed for opposite edges for this loopback.
Bidirectional loopback enables the transmit side clock and data to be looped back as the output at the receive
interface. The output of the demapper is looped back as transmit data (as with Line Loopback, the RnCLKI and
TnCLKI control bits must be programmed for opposite edges).
COMBUS SDH/SONET Local Loopback is enabled when control bit CLPBK (bit 4, 019H) is written with a 1.
This mode is valid in either the add bus or drop bus timing modes. Timing is derived from the selected mode.
The VT/TU are mapped and demapped according to the VT/TU selection registers. No VT/TU are passed to
the demapper from either of the drop buses during COMBUS loopback. COMBUS loopback is valid only when
control bit DV1SEL (bit 2, register 019H) is a 1. COMBUS loopback is valid from A Add to A Drop and B Add to
B Drop.
RESETS
The TEMx28 has several reset options. These include the following:
Drop Bus
•
•
•
•
•
•
•
•
Add Bus
Hardware Reset (RESET lead)
Software Reset (RESETH), Bit 0 - 006H
A and B Drop Reset (DRESET), Bit 0 - 039H
A and B Add Reset (TRESET), Bit 0 - 03CH
Per Channel A Drop Reset (DACHnR), Bit 0 - X+011H
Per Channel B Drop Reset (DBCHnR), Bit 0 - X+081H
Per Channel Add Reset (TnRESET), Bit 0 - X+009
Reset all Channel Counters (RESETC), bit 5 - 01AH
Proprietary TranSwitch Corporation Information for use Solely by its Customers
1
0
CLPBK
Figure 33. Loopback, Line AIS and PRBS Generator/Analyzer
Combus
Local
Loopback
Mapper
Demapper
AIS from Rx Alarms
TnSAIS
0
1
1
RnAISE
0
Generator
PRBS
“1”
DATA SHEET
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“1”
TnAISE
0
1
TnTPG
PRBSG
RnSAIS
1
0
“1”
1
0
0
1
PRBSA
0
1
Channel n
LnLBK
Line
Loopback
Analyzer
PRBS
0
1
PRBSG
TnTPG
“1”
RnLAIS (Only when LnLBK=1)
1
0
FnLBK
1
0
Facility
Loopback
TXC-04222-MB, Ed. 6
T1/E1
Tx
T1/E1
Rx
Line
Line
TXC-04222
TEMx28
June 2003