
PEB 2255
FALC-LH V1.3
Functional Description E1
Data Sheet
9
5
2000-07
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 automatically to Master mode.
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.
4.5.3
The FALC
-LH offers six error counters each of them has a length of 16 bit. They record
code violations, framing bit errors, E-bit errors, CRC
4
bit errors and CRC
4
error events
which are flagged in the different SA6 bit combinations. Each of the error counter 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
4.5.4
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, E bit error, 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
4.5.5
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 clock is derived
from signal RCL
K
.
4.5.6
The FALC
-LH generates and detects a framed or unframed in-band loop up/activate
and down/deactivate pattern with bit error rates up to1/100. Framed or unframed in-band
loop code is selected by LCR1.FLLB. Replacing transmit data with the in-band loop
codes is done by FMR3.
X
LD/
X
L
U
.
The FALC
-LH also offers the ability to generate and detect a flexible in-band loop up
and down pattern (if LCR1.LLBP
=
1) or a default pattern 00001 for up and 001 for down
(if LCR1.LLBP
=
0).
In-Band Loop Generation and Detection