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FALC
56
PEF 2256 H/E
T1/J1 Registers
User’s Manual
Hardware Description
365
DS1.1, 2003-10-23
have been based on an alias framing pattern, setting of FMR0.FRS
leads to synchronization on the next candidate available. However,
only the previously assumed candidate is discarded in the internal
framing pattern memory. The latter procedure can be repeated until
the framer locks on the right pattern (no extensive CRC errors).
Therefore bit FMR1.CRC must be set.
11 = F24:
Synchronization is achieved on verification the framing pattern
and
the CRC6 bits. Synchronous state is reached when framing pattern
and CRC6 checksum are correctly found. For correct operation the
CRC check must be enabled by setting bit FMR1.CRC.
DAIS
Disable AIS to System Interface
0 =
AIS is automatically inserted into the data stream to RDO if
FALC
56 is in asynchronous state.
1 =
Automatic AIS insertion is disabled. Furthermore, AIS insertion
can be initiated by programming bit FMR2.SAIS.
SAIS
Send AIS Towards System Interface
Sends AIS (blue alarm) on output RDO towards system interface.
This function is not influenced by bit FMR2.DAIS.
PLB
Payload Loop-Back
0 =
Normal operation. Payload loop is disabled.
1 =
The payload loop-back loops the data stream from the receiver
section back to transmitter section. Looped data is output on pin
RDO. Data received on port XDI, XSIG, SYPX and XMFS is
ignored. With FMR4.TM = 1 all 193 bits per frame are looped
back. If FMR4.TM = 0 the DL- or FS- or CRC-bits are generated
internally. AIS is sent immediately on port RDO by setting the
FMR2.SAIS bit. During payload loop is active the receive time
slot offset (registers RC(1:0)) should not be changed. It is
recommended to write the actual value of XC1 into this register
once again, because a write access to register XC1 sets the
read/write pointer of the transmit elastic buffer into its optimal
position to ensure a maximum wander compensation (the write
operation forces a slip).
AXRA
Automatic Transmit Remote Alarm
0 =
Normal operation
1 =
The remote alarm (yellow alarm) bit is set automatically in the
outgoing data stream for the duration of the alarm but at least