XRT79L71_1 Datasheet, PDF (168/434 Pages) Exar Corporation – 1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC -

XRT79L71
1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - REGISTER/MAP DESCRIPTION
TRANSMIT E3, ITU-T G.751 RELATED REGISTERS
Transmit E3 Configuration Register - G.751 (Address = 0x1130)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
TxBIP-4
Enable
TxASrcSel[1:0]
TxNSrcSel[1:0]
BIT 2
TxAIS
Enable
BIT 1
TxLOS
Enable
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
REV. 1.0.0
BIT 0
TxFAS
Source
Sel
R/W
0
BIT NUMBER
NAME
7
TxBIP-4 Enable
6-5
TxASrcSel[1:0]
TYPE
R/W
R/W
DESCRIPTION
Transmit BIP-4 Enable:
This READ/WRITE bit-field permits the user to configure the
Transmit E3 Framer block to do the following:
a. To compute the BIP-4 value over a given E3 frame.
b. To insert this BIP-4 value into the last nibble-field within
the very next E3 frame.
0 - Does not configure this option. In this case, the last nibble of
each Outbound E3 frame will contain payload data.
1 - Configures the Transmit E3 Framer block to compute and
insert the BIP-4 value.
Transmit A Bit Source Select[1:0]:
These two READ/WRITE bit-fields permit the user to specify the
source or type of data that is being carried via the A bits, within
each Outbound E3 data stream, as indicated below.
TxASrcSel[1:0]
Resulting Source of A Bit
0
0
The "TxA" bit-field, within the "Transmit E3
Service Bit" register (Address = 0x1135).
0
1 Not Valid - Do not use
The "A" bit is sourced via the "Transmit
1
0
Payload Data Input Interface" block.
This is discussed in greater detail in
Section _.
The Receive E3 Framer block. In this
case, the A bit will transmit the FEBE
indicator to the remote terminal
1
1
equipment. The A bit will be set to "1"
when the Receive E3 Framer block
detects a BIP-4 error, and will be set to "0"
when the Receive E3 Framer block
detects un-erred E3 frames.
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