XRT83VSH28
28
REV. 2.0.0
8-CHANNEL E1 SHORT-HAUL LINE INTERFACE UNIT
NOTE: VDD=3.3V ±5%, TA=25°C, Unless Otherwise Specified
3.2
HDB3 Encoder
In single rail mode, the LIU can encode the TPOS input signal to AMI or HDB3 data. With HDB3 encoding
selected, any sequence with four or more consecutive zeros in the input will be replaced with 000V or B00V,
where "B" indicates a pulse conforming to the bipolar rule and "V" representing a pulse violating the rule. An
example of HDB3 encoding is shown in Table 6.
TABLE 5: TIMING SPECIFICATIONS FOR TCLK/TPOS/TNEG
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
TCLK Duty Cycle
TCDU
30
50
70
%
Transmit Data Setup Time
TSU
50
-
ns
Transmit Data Hold Time
THO
30
-
ns
TCLK Rise Time (10% to 90%)
TCLKR
--
40
ns
TCLK Fall Time (90% to 10%)
TCLKF
--
40
ns
TABLE 6: EXAMPLES OF HDB3 ENCODING
NUMBER OF PULSES BEFORE
NEXT 4 ZEROS
Input
0000
HDB3 (Case 1)
Odd
000V
HDB3 (Case 2)
Even
B00V