T1/E1 Short Haul Transceiver with Crystal-less Jitter Attenuation — LXT350
Table 9. Control Register #1 Read/Write, Address (A7-A0) = x010000x
Jitter Attenuator
Bit
Name
Function
JASEL0 JASEL1 Position
0
1
2
3
EC1
EC2
EC3
-
1
1
0
0
1
Transmit
Receive
Disabled
Sets mode (T1 or E1) and equalizer
(see Table 10 below for control codes).
X
Reserved, set this bit to 0, ignore when reading.
1 = Enable Unipolar I/O mode and allow insertion/detection of BPVs.
0 = Enable Bipolar I/O mode
4
5
UNIENB
1 = Enable B8ZS/HDB3 encoders/decoders and force Unipolar I/O
mode.
ENCEN
B
0 = Disable B8ZS/HDB3 encoders/decoders
6
7
JASEL0
JASEL1
Select jitter attenuation circuitry position in data path or disables the
JA. See right hand section of table for codes.
Table 10. Equalizer Control Input Settings
EC3
EC2
EC1
Function
Pulse
Cable
Coding1
0
0
1
1
1
1
0
1
0
0
1
1
0
1
0
1
0
1
E1
T1
T1
T1
T1
T1
ITU Rec G.703
0-133 ft / 0.6 dB
75 Ω Coax/120 Ω TP
100 Ω TP
HDB3
B8ZS
B8ZS
B8ZS
B8ZS
B8ZS
133-266 ft / 1.2 dB
266-399 ft / 1.8 dB
399-533 ft / 2.4 dB
533-655 ft / 3.0 dB
100 Ω TP
100 Ω TP
100 Ω TP
100 Ω TP
1. When enabled.
Table 11. Control Register #2 Read/Write, Address (A7-A0) = x010001x
Pattern
Bit
Name
Function
EPAT0 EPAT1
Selected
1 = Enable Remote loopback mode
0 = Disable Remote loopback mode
0
1
ERLOOP1
ELLOOP1
0
0
0
1
Transmit TPOS/TNEG
1 = Enable Local loopback mode
0 = Disable Local loopback mode
Detect and transmit QRSS
1 = Enable Analog loopback mode
0 = Disable Analog loopback mode
In-band Loop Up Code
00001
2
3
EALOOP
-
1
1
0
1
In-band Loop Down Code
001
Reserved, set to 0, ignore when reading.
1. To enable Dual loopback (DLOOP), set both ERLOOP = 1 and ELLOOP = 1.
Datasheet
29
ETC [ ETC ]
