XR-T6165 Datasheet, PDF (11/16 Pages) Exar Corporation – Codirectional Digital Data Processor

XR-T6165
Transmitter Code Conversion
Figure 7 shows the transmitter code conversion process
that CCITT G.703 specifies for a 64kbps codirectional
interface.
Step 1 - A 64kbps bit period is divided into four unit
intervals.
Step 2 - A binary 1 is coded as a 1100.
Step 3 - A binary 0 is coded as a 1010.
Step 4 - The binary signal is converted into a three-level
signal by alternating the polarity of consecutive blocks.
Step 5 - The alternation in polarity of the blocks is violated
every eighth block. The violation block marks the last bit
in an octet.
Bit Number
78
1
2
3
4
5
67
8
1
64kbps data
10
0
1
0
0
1
11
0
1
Steps 1-3
Step_ÎÎÎ4 _{ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ}
Step_ÎÎÎ5 _{ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ}
Octet Timin^ÎÎg ^{ÎÎVioÎÎlatiÎÎon ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎViolÎÎationÎÎÎÎÎÎ}
Figure 7. Transmitter Code Conversion for a 64kbps Bipolar Line Signal
Rev. 2.02
11