
xr
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L52
REV. 1.0.1
389
This read/write bit field allows the user to transmit an LOS (Loss of Signal) pattern to the remote terminal, upon
software control.
Table 76
relates the contents of this bit field to the Transmit E3 Framer block's action.
N
OTE
:
When this bit is set, it overrides all of the other bits in this register.
6.2.4.2.1.3
Transmitting FEBE (Far-End Block Error) and FERF (Far-End Receive Failures) indicators
via Software control
The "TxE3 Configuration" register (Address = 0x30) contains a register bit (Bit 0 - TxMARx) that permits the us-
er to control the state of the FEBE and FERF bit-fields, in the outbound E3 data stream.
The bit-format of the "TxE3 Configuration" register is presented below.
This read/write bit-field permits the user to configure the XRT72L52 device to do one of the following.
A.
Set the "FEBE" and "FERF" bit-fields (within the MA byte of "outbound" E3 frames) to the appropriate state
based upon conditions detected by the "Receive DS3/E3 Framer" block.
B.
To (via software-control) set the states of the "FEBE" and "FERF" bit-fields (within the MA byte of "out-
bound" E3 frames).
Setting this bit-field to "1" configures the Transmit DS3/E3 Framer block to automatically set the FEBE and
FERF bit-fields (within the outbound E3 data stream) to states based upon conditions detected by the Receive
DS3/E3 Framer block.
N
OTE
:
In this mode, the Transmit DS3/E3 Framer block will set and clear the FERF and FEBE bit-fields in response to the
following conditions.
A. FERF bit-field
If the Receive DS3/E3 Framer block (in the same channel) is currently experiencing an LOS, AIS or LOF con-
dition, then the Transmit DS3/E3 Framer block will automatically set the FERF bit-field (in the outbound E3
frame) to "1". Conversely, if the Receive DS3/E3 Framer block is not experiencing any of these conditions,
then the Transmit DS3/E3 Framer block will set the FERF bit-field (in the outbound E3 frame) to "0".
B. FEBE bit-field
If the Receive DS3/E3 Framer block detects a BIP-8 error in the incoming E3 frame, then the Transmit DS3/E3
Framer block will automatically set the FEBE bit-field (in the outbound E3 frame) to "1". Conversely, if the Re-
ceive DS3/E3 Framer block does not detect a BIP-8 error in the incoming E3 frame, then the Transmit DS3/E3
Framer block will set the FEBE bit-field (in the outbound E3 frame) to "0".
T
ABLE
76: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
1 (T
X
LOS)
WITHIN
THE
T
X
E3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
E3 F
RAMER
B
LOCK
'
S
A
CTION
B
IT
1
T
RANSMIT
E3 F
RAMER
'
S
A
CTION
0
Normal Operation:
The Overhead bits are either internally generated, or they are inserted via the Transmit Overhead Data Input
Interface or the Transmit HDLC Controller blocks. The Payload bits are received from the Transmit Payload
Data Input Interface.
Transmit LOS Pattern:
When this command is invoked the Transmit E3 Framer will do the following.
Set all of the overhead bytes to "0" (including the FA1 and FA2 bytes)
Overwrite the E3 payload bits with an "all zeros" pattern.
1
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Not Used
TxDL in NR
Not Used
TxAIS Enable
TxLOS
Enable
TxMARx
RO
RO
RO
R/W
RO
R/W
R/W
R/W
0
0
0
0
0
0
0
0