xrt83l30 Exar Corporation, xrt83l30 Datasheet - Page 27

• Manufacturer Part Number: xrt83l30
• Description: Xrt83l30 -single-channel T1/e1/j1 Long-haul, Short-haul Line Interface Unit
• Manufacturer: Exar Corporation

REV. 1.0.1
TRANSMIT HDB3/B8ZS ENCODER
The Encoder function is available in both Hardware and Host modes basis by controlling the TNEG/CODE pin
or CODES interface bit. The encoder is only available in single-rail mode. In E1 mode and with HDB3 encoding
selected, any sequence with four or more consecutive zeros in the input serial data from TPOS/TDATA, will be
removed and replaced with 000V or B00V, where “B” indicates a pulse conforming with the bipolar rule and “V”
representing a pulse violating the rule. An example of HDB3 Encoding is shown in
input data sequence with eight or more consecutive zeros will be removed and replaced using the B8ZS
encoding rule. An example of Bipolar with 8 Zero Substitution (B8ZS) encoding scheme is shown in
Writing a “1” into the CODES interface bit or connecting the TNEG/CODE pin to a “High” level selects the AMI
coding for both E1 or T1 systems.
DRIVER FAILURE MONITOR (DMO)
F
IGURE
TPOS/TDATA
TNEG
12. T
or
TCLK
SINGLE-CHANNEL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
RANSMIT
HDB3 (case1)
HDB3 (case2)
Input
C
LOCK AND
T
SU
AMI Output
AMI Output
N
C
C
I
B8ZS
B8ZS
T
NPUT
T
Input
Input
UMBER OF PULSE BEFORE NEXT
ASE
ASE
ABLE
ABLE
1
2
D
T
3: E
4: E
ATA
HO
XAMPLES OF
XAMPLES OF
T
P
IMING
RECEDING
even
odd
24
+
+
-
-
P
HDB3 E
B8ZS E
ULSE
4
ZEROS
NCODING
NCODING
N
000VB0VB
000VB0VB
000+ -0- +
000- +0+ -
00000000
00000000
EXT
8 B
ITS
N
EXT
B00V
0000
000V
TCLK
Table
4
BITS
R
3. In a T1 system, an
XRT83L30
TCLK
Table
F
4.