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TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L52
REV. 1.0.1
63
2.3.3.1
Receive E3 Configuration & Status Register 1 (E3, ITU-T G.832)
Bit 7 - 5 - RxPLDType[2:0] (Received Payload Type[2:0])
These three Read-Only bit-fields contain the Payload Type value within the MA byte of the most recently re-
ceived E3 frame.
N
OTES
:
1. The Payload Type Mismatch interrupt will be generated if the contents of these bit-fields differ from that of the
Expected Payload Types in Bits 2 through 0 within this Register.
2. These bit-fields are ignored is the channel is configured to support the October 1998 version of the ITU-T G.832
framing format for E3.
Bit 4 - RxFERF Algo
This Read/Write bit-field allows the user to select one of the two RxFERF Declaration Algorithms:
Writing a "0" to this bit-field selects the following RxFERF Declaration algorithm:
The Receive DS3/E3 Framer declares a Far End Receive Failure (FERF) if the FERF bit-field, within the MA
byte is set to "1" for 3 consecutive incoming E3 Frames. Likewise, the Receive DS3/E3 Framer block will
negate the Far End Receive Failure condition if the FERF bit-field, within the MA byte is set to "0" for 3 con-
secutive incoming E3 Frames.
Writing a "1" to this bit-field selects the following RxFERF Declaration algorithm:
The Receive DS3/E3 Framer block declares a Far End Receive Failure (FERF) if the FERF bit-field, within
the MA byte is set to "1" for 5 consecutive E3 Frames. Likewise, the Receive E3/DS3 Framer block will
negate the Far End Receive Failure condition if the FERF bit-field, within the MA byte is set to "0" for 5 con-
secutive incoming E3 Frames.
Bit 3 - RxTMark Algorithm
This Read/Write bit-field allows the user to select the number of consecutive incoming E3 frames, that the Tim-
ing Marker bit-field (within the MA byte-field) must be of a given logic state, before it is validated by the Receive
DS3/E3 Framer block. Once the Receive DS3/E3 Framer block has validated the state of the Timing Marker
bit-field, then it will write this logic state into Bit 1 (RxTMark) within the Rx E3 Configuration & Status Register 2
(Address = 0x11)
Writing a "0" into this bit-field causes the Receive DS3/E3 Framer block to validate the Timing Marker value af-
ter receiving 3 consecutive incoming E3 frames, with the Timing Marker bit-field of a given value. Writing a "1"
into this bit-field causes the Receive DS3/E3 Framer block to validate the Timing Marker value after receiving 5
consecutive incoming E3 frames, with the Timing Marker bit-field of a given value.
N
OTE
:
This bit-field is ignored if the channel is configured to support the October 1998 version of the ITU-T G.832 framing
format for E3.
Bits 2 - 0: RxPLDExp[2:0]
This Read/Write bit-field allows the user to specify the Payload Type that is expected in the MA bytes, of each
incoming E3 frame.
If the Receive DS3/E3 Framer detects a Payload Type that differs from the values within these bit-fields, then
the Framer will generate the Payload Type Mismatch interrupt.
RXE3 CONFIGURATION & STATUS REGISTER 1 (ADDRESS = 0X10)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
RxPLDType[2:0]
RxFERF
Algo
RxTMark
Algo
RxPLDExp[2:0]
RO
RO
RO
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
1
0