PEB22554 SIEMENS [Siemens Semiconductor Group], PEB22554 Datasheet - Page 96

• Manufacturer Part Number: PEB22554
• Description: ICs for Communications
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

4.3
The following is a suggestion for a basic initialization to meet most of the E1
requirements. Depending on different applications and requirement any other
initialization can be used.
LIU Initialization
FMR0.XC0/
FMR0.RC0/
LIM1.DRS
FMR3.CMI
PCD = 0x0A
PCR = 0x15
LIM1.RIL2-0 = 0x02 LOS threshold of 0.6 V (fulfills G.775).
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
QuadFALC driver code of the Evaluation System EASY22554 and application notes)
and helps to reduce the software load. They are very helpful especially to meet
requirements as specified in ETS300 011.
XSP.AXS = 1
XSP.EBP = 1
FMR2.AXRA = 1
FMR2.FRS1/2 = 10
FMR1.AFR = 1
Semiconductor Group
Specific E1 Initialization
ETS300 011 C4.x for instance requires the sending of E-Bits in
TS0 if CRC4 errors have been detected. By programming
XSP.AXS = 1 the submultiframe status is inserted automatically
in the next outgoing multiframe.
If the QuadFALC has reached asynchronous state the E-Bit is set
to 0 if XSP.EBP = 0 and set to 1 if XSP.EBP = 1. ETS300 011
requires that the E-Bit is set to 1 in asynchronous state.
The transmission of RAI via the line interface is done
automatically by the QuadFALC 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 CRC4 multiframing could be found within 8ms.
Together with FMR2.AXRA = 1 this mode is essential to meet
ETS300 011 and reduces the processor load heavily.
The QuadFALC 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 QuadFALC supports
AMI, HDB3, CMI (with and without HDB3 precoding) and NRZ.
LOS detection after 176 consecutive “zeros” (fulfills G.775 spec).
LOS recovery after 22 “ones” in the PCD intervall. (fulfills G.775).
96
Operational Description E1
PEB 22554
09.98