
á
PRELIMINARY
DS3 UNI FOR ATM
XRT7245
REV. 1.03
81
3.3.2.30
Tx DS3 LAPD Configuration Register
Bit 3—Auto Retransmit
The “Read/Write” bit-field allows the user to configure
the LAPD Transmitter to either transmit the LAPD
Message frame only once; or repeatedly at one-
second intervals.
Writing a “0” to this bit-field configures the LAPD
Transmitter to either transmit the LAPD Message
frame only once. Afterwards, the LAPD Transmitter
will halt transmission, until it has commanded
transmit another LAPD Message frame.
Writing a “1” to this bit-field configures the LAPD
Transmitter to transmit the LAPD Message frame re-
peatedly at one second intervals. In this configuration,
the LAPD Transmitter will repeat its transmission of
the LAPD Message frame until it has been disabled.
Bit 2:1 = TxLAPD Type[1, 0]
These two “Read/Write” bit-fields allow the user to
specify the type of LAPD Message frame that he/she
wishes to transmit to the “Far-End” Terminal, as tabu-
lated below.
For information on the LAPD Transmitter, please see
Section 6.4.3.1.3.
Bit 0—TxLAPD Enable
This “Read/Write” bit-field allows the user to enable or
disable the LAPD Transmitter. The LAPD Transmitter
must be enabled before it can be commanded to
transmit a LAPD Message frame (containing a PMDL
message) via the outbound DS3 frames, to the “Far-
End” Terminal.
Writing a “0” disables the LAPD Transmitter (default
condition). Writing a “1” enables the LAPD Transmitter.
For information on the LAPD Transmitter, please see
Section 6.4.3.1.3.
3.3.2.31
Tx DS3 LAPD Status/Interrupt Register
Bit 3—TxDL Start
This “Read/Write” bit-field allows the user to invoke
the “Transmit LAPD Message” command. Once the
user invokes this command, the LAPD Transmitter
will do the following:
Address = 1Eh, Tx DS3 LAPD Configuration Register
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Unused
Auto Retransmit
TxLAPD Type[1:0]
TxLAPD Enable
RO
RO
RO
RO
RO
R/W
R/W
R/W
0
0
0
0
1
0
0
0
T
X
LAPD T
YPE
[1, 0]
LAPD M
ESSAGE
F
RAME
T
YPE
S
IZE
OF
I
NFORMATION
P
AYLOAD
00
Test Signal Identification
76 bytes
01
Idle Signal Identification
76 bytes
10
CL Path Identification
76 bytes
11
ITU-T Path Identification
82 bytes
Address = 1Fh, Tx DS3 LAPD Status/Interrupt Register
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Unused
TxDL Start
TxDL Busy
TxLAPD Interrupt
Enable
TxLAPD Interrupt
Status
RO
RO
RO
RO
R/W
RO
R/W
RUR
0
0
0
0
0
0
0
0