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FOUR CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L54
PRELIMINARY
REV. P1.1.2
96
the Out-of-Frame (OOF) Condition, since the last time
this register was read. Therefore, this bit-field will be
asserted under either of the following two conditions:
1. When the Receive DS3/E3 Framer block has
detected the appropriate conditions to declare an
OOF Condition.
2. When the Receive DS3/E3 Framer block has
transitioned from the OOF Condition (Frame
Acquisition Mode) into the In-Frame Condition
(Frame Maintenance mode).
NOTE: For more information of the OOF Condition, please
see Section 4.3.2.2.
Bit 2 - LOF (Change in LOF Condition) Interrupt
Status
This Reset-upon-Read bit-field will be set to "1" if a
Change in LOF Condition interrupt has occurred
since the last read of this register.
The Receive DS3/E3 Framer block will generate the
Change in LOF Condition interrupt is response to ei-
ther of the following two occurrences.
1. Whenever the Receive DS3/E3 Framer block
transitions from the OOF Condition state into the
LOF Condition state, within the E3 Framing
Acquisition/Maintenance algorithm (per Figure
114).
2. Whenever the Receive DS3/E3 Framer block
transitions from the FA1, FA2 Octet Verification
state to the In-frame state, within the E3 Framing
Acquisition/Maintenance algorithm (per Figure
114).
Bit 1 - LOS (Change in LOS Condition) Interrupt
Status
This Reset Upon Read bit will be set to "1", if the Re-
ceive DS3/E3 Framer block has detected a Change in
the LOS Status condition, since the last time this reg-
ister was read. This bit-field will be asserted under ei-
ther of the following two conditions:
1. When the Receive DS3/E3 Framer block detects
the occurrence of an LOS Condition (e.g., the
occurrence of 32 consecutive spaces in the
incoming E3 data stream), and
2. When the Receive DS3/E3 Framer block detects
the end of an LOS Condition (e.g., when the
Receive DS3/E3 Framer block detects a string 32
bits that does not contain a string of four consec-
utive "0’s").
The local P can determine the current state of the
LOS condition by reading bit 6 of the Rx E3 Configu-
ration and Status Register (Address = 0x11).
NOTE: For more information in the LOS of Signal (LOS)
Alarm, please see Section 4.3.2.7.
Bit 0 - AIS (Change in AIS Condition) Interrupt
Status
This Reset Upon Read bit field will be set to "1", if the
Receive DS3/E3 Framer block has detected a
Change in the AIS condition, since the last time this
register was read. This bit-field will be asserted un-
der either of the following two conditions:
1. When the Receive DS3/E3 Framer block first
detects an AIS Condition in the incoming E3 data
stream.
2. When the Receive DS3/E3 Framer block has
detected the end of an AIS Condition in the
incoming E3 data stream.
The local P can determine the current state of the
AIS condition by reading bit 7 of the Rx E3 Configura-
tion and Status Register (Address = 0x11).
NOTE: For more information on the AIS Condition please
see Section 4.3.2.8.
2.4.4.6
Receive E3 Interrupt Status Register -
2 (E3, ITU-T G.751)
Bit 3 - FERF (Change in FERF Condition) Interrupt
Status
This Reset Upon Read bit will be set to '1' if the Re-
ceive DS3/E3 Framer block has detected a Change in
the Rx FERF Condition, since the last time this regis-
ter was read.
This bit-field will be asserted under either of the fol-
lowing two conditions.
RXE3 INTERRUPT STATUS REGISTER - 2 (ADDRESS = 0X15)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1BIT 0
Not Used
FERF
Interrupt
Status
BIP-4
Error
Interrupt
Status
Framing
Error
Interrupt
Status
Not Used
RO
RUR
0
0000
000