XRT79L71_1 Datasheet, PDF (153/434 Pages) Exar Corporation – 1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC -

REV. 1.0.0
XRT79L71
1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - REGISTER/MAP DESCRIPTION
Transmit DS3 F-Bit Mask # 3 Register (Address = 0x1138)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
F_Bit
Mask [15]/
FEBE Bit 3
(C43)
F_Bit
Mask [14]/
FEBE Bit 2
(C42)
F_Bit
Mask [13]/
FEBE Bit 1
(C41)
F_Bit
Mask [12]
F_Bit
Mask [11]/
CP Bit #
3(C33)
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
BIT 2
F_Bit
Mask [10]/
CP Bit #
2(C32)
R/W
0
BIT 1
F_Bit
Mask [9]/CP
Bit # 1(C31)
R/W
0
BIT 0
F_Bit
Mask [8]
R/W
0
BIT NUMBER
NAME
7
F Bit Mask[15]/FEBE Bit
# 3 (C43)
TYPE
R/W
DESCRIPTION
Transmit F-Bit Error - Bit 16/FEBE Bit # 3 (C43):
The exact function of this register bit depends upon the following
parameters.·
• Whether the XRT79L71 has been configured to operate in the
Clear-Channel Framer Mode, or not.
• Whether Bit 7 (TxOHSrc), within the Test Register (Address =
0x110C) is set to "1" or "0".
If the XRT79L71 is NOT configured to operate in the Clear-
Channel Framer Mode, OR if TxOHSrc = "0" - Transmit F-Bit
Error - Bit 16:
This READ/WRITE bit-field permits the user to configure the
Transmit DS3 Framer block to transmit DS3 frames with an
erred F bit.
This F-bit corresponds with the 16th F-bit, within a given out-
bound DS3 frame. The Transmit DS3 Framer block will perform
an XOR operation with the contents of this bit-field and value of
the 16th F-bit. The results of this calculation will be written back
into the 16th F-bit position, within each outbound DS3 frame.
The user should set this bit-field to "0" for normal (e.g., un-erred)
operation.
If the XRT79L71 is configured to operate in the Clear-Chan-
nel Framer Mode, AND if TxOHSrc = "1" - Insert Enable for
FEBE Bit # 3 or C43 bit:
This READ/WRITE bit-field permits the user to configure the
Transmit Payload Data Input Interface block to externally accept
an overhead bit and insert it into the FEBE Bit # 3 (or C43) bit-
fields, within the outbound DS3 data-stream.
0 - Configures the Transmit Direction circuitry to externally
accept and insert data into this overhead bit-field.
1- Configures the Transmit Direction circuitry to NOT externally
accept and insert data into this overhead bit-field.
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