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DS3171/DS3172/DS3173/DS3174
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7 MAJOR LINE INTERFACE OPERATING MODES
The line interface modes provide the following functions:
1. Enabling/disabling of RX and TX LIU.
2. Enabling/Disabling of jitter attenuator (JA).
3. Selection of the location of JA, i.e. RX or TX path.
4. Selection of the line coding type: i.e. B3ZS/HDB3/AMI or UNI.
7.1 DS3HDB3/B3ZS/AMI LIU Mode
The TZCDS and RZCDS bits in the line encoder/decoder block select between no encoding/decoding (AMI) and
encoding/decoding (B3ZS, HDB3). When the HDB3/B3ZS line decoder/encoder is enabled, the framing modes (FM
bits) select between B3ZS and HDB3 line coding. The DS3 modes select the B3ZS line code while the E3 modes
select the HDB3 line code.
Table 7-1. HDB3/B3ZS/AMI LIU Mode Configuration Registers
MODE LM[2:0]
TZSD &
TLEN
PORT.CR2
JA Off, B3ZS or HDB3
001
0
0
JA RX, B3ZS or HDB3
010
0
0
JA TX, B3ZS or HDB3
011
0
0
JA Off, AMI
001
1
0
JA RX, AMI
010
1
0
JA TX, AMI
011
1
0