Datasheet

DS26518 8-Port T1/E1/J1 Transceiver
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Register Name:
LRISMR
Register Description:
LIU Receive Impedance and Sensitivity Monitor Register
Register Address:
1007h + (20h x (n - 1)) : where n = 1 to 8
Bit # 7 6 5 4 3 2 1 0
Name — RIMPON — — — RIMPM2 RIMPM1 RIMPM0
Default 0 0 0 0 0 0 0 0
Bit 6: Receive Internal Impedance Match On (RIMPON)
0 =
Receive internal impedance termination is disabled (high impedance).
1 =
Receive internal impedance termination is enabled.
Bits 2 to 0: Receive Impedance Selection (RIMPM[2:0]). These bits are used to select the receive impedance
termination. They must be set according to the cable impedance even if internal termination resistance is disabled
(RIMPON = 0). See
Table 10-21.
Table 10-21. Receive Impedance Selection
RIMPON RIMPRM[2:0]
RECEIVE IMPEDANCE SELECTED (
Ω)
0
x00
75
Ω external termination (no internal impedance match)
0
x01
100
Ω external termination (no internal impedance match)
0
x10
110
Ω external termination (no internal impedance match)
0
x11
120
Ω external termination (no internal impedance match)
1
000
75
Ω, with external 120Ω resistor
1
001
100
Ω, with external 120Ω resistor
1
010
110
Ω, with external 120Ω resistor
1
011
120
Ω, with external 120Ω resistor
1
100
75
Ω internal termination
1
101
100
Ω internal termination
1
110
110
Ω internal termination
1
111
120
Ω internal termination