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Data Sheet
81
Rev. 1.0, 2005-06-02
OctalLIU
TM
PEF 22508 E
Functional Description
If a remote loop is activated by an automatic loop switching the register bit LIM0.JATT controls also if the jitter
attenuator is active or not, see also Figure 31.
If ALS.LILS is set (ALS), the remote loop is activated after an activation In-Band loop code (see ANSI T1 404,
chapter 9.4.1.1.) was detected from the line side and if the local loop is not activated by LIM0.LL = 1. The remote
loop is deactivated after a deactivation In-Band loop code (see ANSI T1 404, chapter 9.4.1.2.) was detected from
the line side. (But if the remote loop is additionally activated by LIM0.RL = 1 the remote loop is still active,
because automatic loop switching is logically ORd with the appropriate loop switching by register bits.).
If ALS.SILS is set, the local loop is activated after an activation In-Band loop code (see ANSI T1 404, chapter
9.4.1.1.) was detected from the system side. The local loop is deactivated after a deactivation In-Band loop code
(see ANSI T1 404, chapter 9.4.1.2.) was detected from the system side. (But if the local loop is additionally
activated by LIM0.LL = 1 the local loop is still active, because automatic loop switching is logically ORd with the
appropriate loop switching by register bits.).
ALS.SILS and ALS.LILS both must not be set to 1 simultaneous.
If ALS.SILS or ALS.LILS are set after an In-Band loop code was detected, no automatic loop switching is
performed.
If ALS.LILS is cleared, an automatic activated remote loop is deactivated.
If ALS.SILS is cleared, an automatic activated local loop is deactivated.
The kind of detected In-Band loop codes is shown in the interrupt status register bits ISR6.(3:0).
To avoid deadlocks in the OctalLIU
TM an activation of the remote loop is not possible by In-band loop codes if the
3.11.3
Remote Loop
In the remote loop-back mode the clock and data recovered from the line inputs RL1/2 or ROID are routed back
to the line outputs XL1/2 or XOID through the analog or digital transmitter, see Figure 36 and Figure 31. As in
normal mode they are also sent to the framer interface. The remote loop-back mode is activated by
Control bit LIM1.RL or
After detection of the appropriate In-band loop code, if enabled by ALS.LILS and if LIM0.LL = 0 (LIM0) (to
Received data can be looped with or without the jitter attenuator (JATT buffer) dependent on LIM1.JATT (LIM1).
Figure 36
Remote Loop
Pulse
Shaper,
LBO
Encoder
XDATA
XL2
OctalLIU_remote_loop
Transmit Line
Interface
DAC
XL1/XOID
Equalizer
Clock &
Data
Recovery
Decoder
RL1/ROID
Receive Line
Interface
DPLL
JATT
Buffer
RDATA
clocking
RL2