XRT79L71_1 Datasheet, PDF (95/434 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
BIT NUMBER
NAME
6
RxABORT
5-4
RxLAPDType[1:0]
3
RxCR Type
2
RxFCS Error
TYPE
R/O
R/O
DESCRIPTION
Receive ABORT Sequence Indicator:
This READ-ONLY bit-field indicates whether or not the Receive
LAPD Controller block has received an ABORT sequence (e.g.,
a string of seven consecutive "0s"), as described below.
0 - Indicates that the Receive LAPD Controller block has NOT
received an ABORT sequence.
1 - Indicates that the Receive LAPD Controller block has
received an ABORT sequence.
NOTES:
1. Once the Receive LAPD Controller block receives an
ABORT sequence, it will set this bit-field "High", until it
receives another LAPD Message.
2. This bit-field is only active if the XRT79L71 has been
configured to operate in the DS3, C-bit Parity Framing
format.
Receive LAPD Message Type Indicator:
These two READ-ONLY bits indicate the type of LAPD Message
that is residing within the Receive LAPD Message buffer. The
relationship between the content of these two bit-fields and the
corresponding message type is presented below.
RxLAPDType[1:0]
Message Type
0
0
0
1
1
0
1
1
CL Path Identification
Idle Signal Identification
Test Signal Identification
ITU-T Path Identification
NOTE: These bit-fields are only active if the XRT79L71 has been
configured to operate in the DS3, C-bit Parity Framing
format.
R/O Received C/R Value:
This READ-ONLY bit-field indicates the value of the C/R bit
(within one of the header bytes) of the most recently received
LAPD Message.
NOTE: This bit-field is only active if the XRT79L71 has been
configured to operate in the DS3, C-bit Parity Framing
format.
R/O Receive Frame Check Sequence (FCS) Error Indicator:
This READ-ONLY bit-field indicates whether or not the most
recently received LAPD Message frame contained an FCS error.
0 - The most recently received LAPD Message frame does not
contain an FCS error.
1 - The most recently received LAPD Message frame does con-
tain an FCS error.
NOTE: This bit-field is only active if the XRT79L71 has been
configured to operate in the DS3, C-bit Parity Framing
format.
86