2.0 Circuit Description
CX28394/28395/28398
2.4 Transmitter
Quad/x16/Octal—T1/E1/J1 Framers
The HDB3 line code replaces four consecutive zeros by 000V or B00V code,
where B is an AMI pulse and V is a bipolar violation (see Figure 2-24). ZCS
encoder selects the code that will force the BPV output polarity opposite to the
prior BPV.
Figure 2-24. Zero Code Substitution Formats
Zero Code Substitution Formats
Octet
1
1
0
0
0
0
0
0
1
0
0
1
AMI
BPV
BPV
BPV
B8ZS
BPV
HDB3
B7ZS
UMC
UMC forces DS0 channels containing 8 zeros to be replaced with the
10011000 code, per Bellcore TA-TSY-000278. Note that RCVR's ZCS decoder
cannot recover original data content from a UMC or B7ZS encoded signal, or
from a PDV-enforced one.
2-52
Conexant
100054E
CONEXANT [ CONEXANT SYSTEMS, INC ]
