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PRELIMINARY
DS3 UNI FOR ATM
XRT7245
REV. 1.03
69
3.3.2.13
Test Cell Error Accumulator—LSB
These “Reset-upon-Read” bit fields, along with those
of the “Test Cell Error Accumulator—MSB” Register
(Address = 0Ch), contains a 16-bit representation of
the number of erred test cells that have been detect-
ed by the “Test Cell Receiver” since the last read of
these registers. This register contains the lower-byte
value for the 16-bit expression.
Note:
The contents of these registers are valid only if the
Test Cell Receiver has acquired “PRBS Lock” with the pay-
load data of the test cells that it has received.
3.3.2.14
Rx DS3 Configuration and Status Register
Bit 7—RxAIS—Receive AIS Signal
This “Read Only” bit-field will be set to “1” if the
Receive DS3 Framer has identified an “AIS” (Alarm
Indication Signal) Condition on the incoming DS3
data stream. For more information into the “AIS” Con-
dition, please see Section 7.1.2.3.2.
Bit 6—RxLOS—Receive LOS Condition
This “Read Only” bit-field will be set to “1” if the Re-
ceive DS3 Framer has identified an “LOS” (Loss of
Signal) Condition in the incoming DS3 data stream.
For more information into the “LOS” Condition,
please see Section 7.1.2.3.1.
Bit 5—RxIdle—Receive Idle Condition
This “Read Only” bit field will be set to “1” if the Re-
ceive DS3 Framer has identified an “Idle” Condition in
the incoming DS3 data stream. For more information
into the “Idle” Condition, please see Section
7.1.2.3.3.
Bit 4—RxOOF—Out of Frame Condition
This “Read Only” bit field will be set to “1” if the
Receive DS3 Framer is in an “Out of Frame” condi-
tion. For more information into the “OOF” Condition,
please see Section 7.1.2.2.
Bit 3—Int (Receive DS3 Framer) LOS Disable
This “Read/Write” bit field allows the user to enable
or disable the “Declaration of an LOS condition”
based upon the Receive DS3 Framer’s detection of
180 consecutive “0s” at the RxPOS and RxNEG inputs.
If the user writes a “1” into this bit-field, then the
Receive DS3 Framer will declare an “LOS Condition”
only if the RLOS input pin (from the XRT7295 DS3
Line Receive IC) is set “high”.
If the user writes a “0” into this bit-field, then the
Receive DS3 Framer will declare an “LOS Condition”
if either (or both) of the following conditions are met:
The Receive DS3 Framer detects 180 con-
secutive “0s” at the RxPOS and RxNEG
inputs, or
The RLOS input pin is asserted (set “high”).
a.
b.
Bit 2—Framing On Parity
This “Read/Write” bit field allows the user to require
that the Receive DS3 Framer include Parity (P-bit)
verification as a condition for declaring itself “In-
Frame”, during Frame Acquisition. This requirement
will be imposed in addition to those criteria selected
via Bits 0 and 1 of this register.
This feature also imposes an additional “Frame Main-
tenance” requirement on the Receive DS3 Framer, in
addition to the requirements specified in the user’s
Address = 0Dh, Test Cell Error Accumulator—LSB
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Test Cell Error—Low Byte
RUR
RUR
RUR
RUR
RUR
RUR
RUR
RUR
0
0
0
0
0
0
0
0
Address = 0Eh, Rx DS3 Configuration and Status Register
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
RxAIS
RxLOS
RxIdle
RxOOF
IntLOS Disable
Framing On Parity
FSync Algo
MSync Algo
RO
RO
RO
RO
R/W
R/W
R/W
R/W
0
1
0
1
0
0
0
0