XRT86VL38
75
OCTAL T1/E1/J1 FRAMER/LIU COMBO - E1 REGISTER DESCRIPTION
REV. V1.2.1
T
ABLE
58: T
RANSMIT
D
ATA
L
INK
B
YTE
C
OUNT
R
EGISTER
(TDLBCR2) H
EX
A
DDRESS
: 0
X
n144
B
IT
F
UNCTION
T
YPE
D
EFAULT
D
ESCRIPTION
-O
PERATION
7
TxHDLC2 BUFAvail/
BUFSel
R/W
0
Transmit HDLC2 Buffer Available/Buffer Select
This bit has different functions, depending upon whether the user is
writing to or reading from this register, as depicted below.
If the user is writing data into this register bit:
0 - Configures the Transmit HDLC2 Controller to read out and trans-
mit the data, residing within “Transmit HDLC2 Buffer # 0", via the
Data Link channel to the remote terminal equipment.
1 - Configures the Transmit HDLC2 Controller to read out and trans-
mit the data, residing within the “Transmit HDLC2 Buffer #1”, via the
Data Link channel to the remote terminal equipment.
If the user is reading data from this register bit:
0 - Indicates that “Transmit HDLC2 Buffer # 0" is the next available
buffer. In this case, if the user wishes to write in the contents of a
new “outbound” Data Link Message into the Transmit HDLC2 Mes-
sage Buffer, he/she should proceed to write this message into
“Transmit HDLC2 Buffer # 0" - Address location: 0xn600.
1 - Indicates that “Transmit HDLC2 Buffer # 1" is the next available
buffer. In this case, if the user wishes to write in the contents of a
new “outbound” Data Link Message into the Transmit HDLC2 Mes-
sage Buffer, he/she should proceed to write this message into
“Transmit HDLC2 Buffer # 1" - Address location: 0xn700.
N
OTE
:
If one of these Transmit HDLC2 buffers contain a message
which has yet to be completely read-in and processed for
transmission by the Transmit HDLC2 controller, then this bit
will automatically reflect the value corresponding to the next
available buffer when it is read. Changing this bit to the in-
use buffer is not permitted.
6-0
TDLBC[6:0]
R/W
0000000
Transmit HDLC2 Message - Byte Count
The exact function of these bits depends on whether the Transmit
HDLC 2 Controller is configured to transmit MOS or BOS messages
to the Remote Terminal Equipment.
In BOS MODE:
These bit fields contain the number of repetitions the BOS message
must be transmitted before the Transmit HDLC2 controller gener-
ates the Transmit End of Transfer (TxEOT) interrupt and halts trans-
mission. If these fields are set to 00000000, then the BOS message
will be transmitted for an indefinite number of times.
In MOS MODE:
These bit fields contain the length, in number of octets, of the mes-
sage to be transmitted. The length of MOS message specified in
these bits include header bytes such as the SAPI, TEI, Control field,
however, it does not include the FCS bytes.