
FALC
56
PEF 2256 H/E
E1 Registers
User’s Manual
Hardware Description
309
DS1.1, 2003-10-23
Receive Spare Bits/Additional Status (Read)
SI(2:1)
Submultiframe Error Indication 1, 2
Not valid if doubleframe format is enabled. In this case, both bits are
set.
When using CRC-multiframe format these bits are set to
0 =
If multiframe alignment has been lost, or if the last multiframe
has been received with CRC error(s).
SI1 flags a CRC error in last submultiframe 1, SI2 flags a CRC
error in last submultiframe 2.
1 =
If at multiframe synchronous state last assigned submultiframe
has been received without a CRC error.
Both flags are updated with the beginning of every received CRC
multiframe.
If automatic transmission of submultiframe status is enabled by
setting bit XSP.AXS, above status information is inserted
automatically in S
i
-bit position of every outgoing CRC multiframe
(under the condition that time slot 0 transparent modes are both
disabled):
SI1
→
S
i
-bit of frame 13, SI2
→
S
i
-bit of frame 15.
LLBDD
Line Loop-Back Deactivation Signal Detected
This bit is set in case of the LLB deactivate signal is detected and then
received over a period of more than 25 ms with a bit error rate less
than 10
-2
. The bit remains set as long as the bit error rate does not
exceed 10
-2
.
If framing is aligned, the time slot 0 is not taken into account for the
error rate calculation.
Any change of this bit causes an LLBSC interrupt.
LLBAD
Line Loop-Back Activation Signal Detected
Depending on bit LCR1.EPRM the source of this status bit changed.
LCR1.EPRM = 0: This bit is set in case of the LLB activate signal is
detected and then received over a period of more than 25 ms with a
bit error rate less than 10
-2
. The bit remains set as long as the bit error
rate does not exceed 10
-2
.
7
0
RSP
SI1
SI2
LLBDD
LLBAD
RSIF
RS13
RS15
(4F)