
x r
PRELIMINAZRY
E3 UNI FOR ATM
XRT7234
REV. P1.0.0
63
read of this register.
The Receive E3 Framer will generate the “Change in LOF Condition” interrupt is response to either of the following
two occurrences.
1.
Whenever the Receive E3 Framer transitions from the “OOF Condition” state into the “LOF Condition”
state, within the “E3 Framing Acquisition/Maintenance” algorithm (per Figure 60).
2.
Whenever the Receive E3 Framer transitions from the “FA1, FA2 Octet Verification” state to the “In-frame”
state, within the “E3 Framing Acquisition/Maintenance” algorithm (per Figure 60).
Bit 1—LOS (Loss of Signal) Interrupt Status
This “Reset Upon Read” bit will be set to “1”, if the Receive E3 Framer has detected a
“Change in the LOS Status” condition, since the last time this register was read. This bit-field will be asserted
under either of the following two conditions:
1.
When the Receive E3 Framer detects the occurrence of an LOS Condition (e.g., the occurrence of 32 consecu-
tive “spaces” in the incoming E3 data stream), and
2.
When the Receive E3 Framer detects the end of an LOS Condition (e.g., when the Receive E3 Framer
detects a string 32 bits that does not contain a string of four consecutive “0s”).
The local
μ
P
can determine the current state of the LOS condition by reading bit 6 of the “Rx E3 Configuration
and Status” Register (Address = 0Eh).
For more information in the “LOS of Signal (LOS) Alarm, please see Section 7.1.2.3.1.
Bit 0—AIS Interrupt Status
This “Reset Upon Read” bit field will be set to “1”, if the Receive E3 Framer has detected a “Change in the AIS” con-
dition, since the last time this register was read. This bit-field will be asserted under either of the following two
conditions:
1.
When the Receive E3 Framer first detects an AIS Condition in the incoming
Bit 4—Idle Condition Interrupt Status, and
2.
When the Receive E3 Framer has detected the end of an “AIS Condition”.
The local
μ
P
can determine the current state of the AIS condition by reading bit 7 of the “Rx E3 Configuration
and Status” Register (Address = 0Eh).
For more information on the “AIS Condition” please see Section 7.1.2.3.2.
3.3.2.21 Rx E3 Interrupt Status Register-2
Bit 6— TTB Change Interrupt Status (Receipt of New Trail Trace Buffer Message interrupt)
This “Reset-upon-Read” bit-field will be set to “1” if a “Receipt of New Trail Trace Buffer Message” interrupt has
occurred since the last read of this register.
The Receive E3 Framer will generate the “Receipt of New Trail Trace Buffer Message” interrupt, if it receives an
Address = 13h, Rx E3 Interrupt Status Register-2
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Unuse
d
TTB Change
Interrupt
Status
LAPD
Interrupt
Status
FEBE
Interrupt
Status
FERF
Interrupt
Status
EM-Byte
Error Inter-
rupt Status
Framing
Byte Error
Interrupt
Status
Rx Pld Mis
Interrupt
Status
RO
RUR
RUR
RUR
RUR
RUR
RUR
RUR
0
0
0
0
0
0
0
0