
Data Sheet
59
Rev. 1.0, 2005-06-02
OctalLIU
TM
PEF 22508 E
Functional Description
Using the receive line monitor mode and the hardware tristate function of transmit lines XL1/2 on the line side and
the tristate functions on the framer side, the OctalLIU
TM supports applications connecting two channels to one
receive and transmission line. In these kind of applications both channels are working in parallel for redundancy
purpose (see Figure 21). While one of them is driving the line, the other one must be switched into transmit line
tristate mode. If both channels are configured identically and supplied with the same system data and clocks, the
transmit path can be switched from one channel to the other without causing a synchronization loss at the remote
end.
Figure 21
Redundancy Application using RLM (shown for one line)
RDOP and FCLKR can be set into tristate mode constantly for redundancy applications using the register bit
DIC3.RRTRI (DIC3) and - if the RTDMT function is selected on one of the multi function port - by RTDMT, see
Chapter 3.12. If the RTDMT function is selected the values of RTDMT and DIC3.RRTRI are logically exored. This
enables an easy redundancy application using only one signal for switching between two devices. If the RTDMT
function is not selected DIC3.RRTRI = 1 set the pins into tristate mode constantly. In this mode “tristate” means
high impedance against V
DD and VSS: No pull up or pull down resistor is active.
Table 14
External Component Recommendations (Monitoring)
Parameter
1)
1) This includes all parasitic effects caused by circuit board design.
Characteristic Impedance (Ohm)
E1
T1
J1
75
120
100
110
R
1 (±1 %) ()
75
120
100
110
R
2 (±1 %) ()
75
120
100
110
R
3 (±1 %) ()
330
510
430
470
t
2 : t1
1 :1
1 : 1
E1/T1/J1
Receive
Line
RL1
RL2
RDOP
RL1
RL2
RDOP
XL1
XL2
E1/T1/J1
Transmit
Line
XDIP
XL1
XL2
XDIP
XLT
(XPA)
active/stand-by
stand-by/actice
FCLKR
XLT
(XPA)
OctalLIU_Receiver_2
RTDMT
low/high
DIC3.RRTRI = 0
DIC3.RRTRI = 1
(RPA)
FCLKX
Framer
1/8OctalLIUTM