7 liu control registers – Maxim Integrated DS21Q55 User Manual
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23.7 LIU Control Registers
Register Name:
LIC1
Register Description:
Line Interface Control 1
Register Address:
78h
Bit #
7
6
5
4
3
2
1
0
Name
L2
L1
L0
EGL
JAS
JABDS
DJA
TPD
Default
0
0
0
0
0
0
0
0
Bit 0/Transmit Power-Down (TPD).
0 = powers down the transmitter and tristates the TTIP and TRING pins
1 = normal transmitter operation
Bit 1/Disable Jitter Attenuator (DJA).
0 = jitter attenuator enabled
1 = jitter attenuator disabled
Bit 2/Jitter Attenuator Buffer Depth Select (JABDS).
0 = 128 bits
1 = 32 bits (use for delay sensitive applications)
Bit 3/Jitter Attenuator Select (JAS).
0 = place the jitter attenuator on the receive side
1 = place the jitter attenuator on the transmit side
Bit 4/Receive Equalizer Gain Limit (EGL). This bit controls the sensitivity of the receive equalizer.
T1 Mode: 0 = -36dB (long haul)
1 = -15dB (limited long haul)
E1 Mode: 0 = -15dB (short haul)
1 = -43dB (long haul)
Bits 5 to 7/Line Build-Out Select (L0 to L2). When using the internal termination the user needs only to select 000 for 75O
operation or 001 for 120O operation below. This selects the proper voltage levels for 75O or 120O operation. Using TT0 and
TT1 of the LICR4 register, users can then select the proper internal source termination. Line build-outs 100 and 101 are for
backwards compatibility with older products only.