XRT79L71_1 Datasheet, PDF (124/434 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
REV. 1.0.0
BIT NUMBER
NAME
7
RxLAPD Any
6-4
3
Unused
Receive LAPD from NR
Byte
2
Receive LAPD Enable
1
Receive LAPD Interrupt
Enable
TYPE
R/W
R/O
R/W
R/W
R/W
DESCRIPTION
Receive LAPD - Any kind:
This READ/WRITE bit-field permits the user to configure the
Receive LAPD Controller block to receive any kind of LAPD
Message (or HDLC Message) with a size of 82 bytes or less. If
the user implements this option, then the Receive LAPD Control-
ler block will be capable of receiving any kind of HDLC Message
(with any value of header bytes). The only restriction is that the
size of the HDLC Message must not exceed 82 bytes.
0 - Does not invoke this Any Kind of HDLC Message feature. In
this case, the Receive LAPD Controller block will only receive
HDLC Messages that contains the Bellcore GR-499-CORE val-
ues for SAPI and TEI.
1-Invokes this Any Kind of HDLC Message feature. In this case,
the Receive LAPD Controller block will be able to receive HDLC
Messages that contain any header byte values.
NOTE: The user can determine the size (or byte count) of the
most recently received LAPD/PMDL Message, by
reading the contents of the Receive LAPD Byte Count
Register (Address = 0x1184).
Receive LAPD Message from NR Byte Select:
This READ/WRITE bit-field permits the user to configure the
Receive LAPD Controller block to extract out the PMDL data
from the NR or GC byte, within the incoming E3 data stream.
0 - The Receive LAPD Controller block will extract PMDL infor-
mation from the GC byte, within the incoming E3 data stream.
1 - The Receive LAPD Controller block will extract PMDL infor-
mation from the NR byte, within the incoming E3 data stream.
Receive LAPD Controller Block Enable:
This READ/WRITE bit-field permits the user to either enable or
disable the Receive LAPD Controller block within the XRT79L71.
If the user enables the Receive LAPD Controller block then it will
immediately begin extracting out and monitoring the data that is
being carried by either the NR or GC bytes (depending upon
user configuration) within the incoming E3 data stream.
0 - Disables the Receive LAPD Controller Block.
1 - Enables the Receive LAPD Controller Block for operation.
Receive LAPD Message Interrupt Enable:
This READ/WRITE bit-field permits the user to either enable or
disable the Receive LAPD Message Interrupt. If the user
enables this interrupt, then the XRT79L71 will generate an inter-
rupt, anytime the Receive LAPD Controller block receives a new
LAPD/PMDL Message.
0 - Disables the Receive LAPD Message Interrupt.
1 - Enables the Receive LAPD Message Interrupt.
NOTE: This bit-field is ignored if the Receive LAPD Controller
block is disabled.
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