
PEB 2255
FALC-LH V1.3
Operational Description E1
Data Sheet
161
2000-07
Table 41
Register
FMR0.
X
C0
FMR0.RC0
LIM1.DRS
FMR3.CMI
E1 Framer Initialization
The selection of the following modes during the basic initialization supports the ETSI
requirements for E-Bit Access, Remote Alarm and Synchronization (please refer also to
FALC
-LH driver code of the Reference System EAS
Y
2255-R1 and application notes)
and helps to reduce the software load. They are very helpful especially to meet
requirements as specified in ETS300 011.
Line Interface Initialization (E1)
Function
The FALC
-LH supports requirements for the analog line
interface as well as the digital line interface. For the analog line
interface the codes AMI and HDB3 are supported. For the digital
line interface modes (dual or single rail) the FALC
-LH supports
AMI, HDB3, CMI (with and without HDB3 precoding) and NR
Z
.
LOS detection after 176 consecutive “zeros” (fulfills G.775 spec).
LOS recovery after 22 “ones” in the PCD interval. (fulfills G.775).
LIM1.RIL2-0
=
03
H
LOS threshold (fulfills G.775
;
see DC characteristics)
PCD
=
0A
H
PCR
=
15
H
Table 42
Framer Initialization (E1)
Register
X
SP.A
X
S
=
1
Function
ETS300 011 C
4
.x for instance requires the sending of E-Bits in
TS0 if CRC
4
errors have been detected. By programming
X
SP.A
X
S
=
1 the submultiframe status is inserted automatically in
the next outgoing multiframe.
If the FALC
-LH has reached asynchronous state the E-Bit is
cleared if
X
SP.EBP
=
0 and set if
X
SP.EBP
=
1. ETS300 011
requires that the E-Bit is set in asynchronous state.
The transmission of RAIvia the line interface is done automatically
by the FALC
-LH in case of Loss of Frame Alignment
(FRS0.LFA
=
1). If basic framing has been reinstalled RAI is
automatically reset.
In this mode a search of double framing is automatically reinitiated
if no CRC
4
multiframing could be found within
8
ms. Together with
FMR2.A
X
RA
=
1 this mode is essential to meet ETS300 011 and
reduces the processor load heavily.
X
SP.EBP
=
1
FMR2.A
X
RA
=
1
FMR2.FRS1/2
=
10
FMR1.AFR
=
1