
PEB 2255
FALC-LH V1.3
Functional Description T1/J1
Data Sheet
150
2000-07
5.5.2
Auto Modes
Automatic remote alarm (
Y
ellow Alarm) access
If the receiver has lost its synchronization (FRS0.LFA) a remote alarm (yellow alarm)
can be sent to the distant end automatically, if enabled by bit FMR2.A
X
RA. In
synchronous state the remote alarm bit is removed.
Automatic AIS to system interface
In asynchronous state the synchronizer enforces an AIS to the receive system
interface
automatically.
However,
received
transparently if bit FMR2.DAIS is set.
Automatic clock source switching
In Slave mode (LIM0.MAS
=
0) the DCO-R synchronizes to the recovered route clock.
In case of Loss of Signal LOS the DCO-R switches to Master mode automatically.
Automatic freeze signaling:
U
pdating of the received signaling information is controlled by the freeze signaling
status. Optionally automatic freeze signaling can be disabled by setting bit SIC3.DAF.
data
may
be
switched
through
5.5.3
The FALC
-LH offers five error counters where each of them has a length of 16 bit. They
record code violations, framing bit errors, CRC6 bit errors, errored blocks and PRBS bit
errors. Each of the error counters is buffered.
U
pdating the buffer is done in two modes:
one second accumulation
on demand via handshake with writing to the DEC register
In the one second mode an internal one second timer updates these buffers and reset
the counter to accumulate the error events in the next one second period. The error
counter can not overflow. Error events occurring during reset are not lost.
Error Counter
5.5.4
The FALC
-LH supports the error performance monitoring by detecting the following
alarms or error events in the received data:
framing errors, CRC errors, code violations, loss of frame alignment, loss of signal, alarm
indication signal, receive and transmit slips.
With a programmable interrupt mask register IMR
4
all these alarms or error events can
generate an Errored Second Interrupt (ISR3.ES) if enabled.
Errored Second
5.5.5
Second Timer
Additionally a one second timer interrupt is generated internally to indicate that the
enabled alarm status bits or the error counters have to be checked. The timing is derived
from RCL
K
.