XRT86VL32_07 Datasheet, PDF (41/174 Pages) Exar Corporation – DUAL T1/E1/J1 FRAMER/LIU COMBO - E1 REGISTER DESCRIPTION

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XRT86VL32
DUAL T1/E1/J1 FRAMER/LIU COMBO - E1 REGISTER DESCRIPTION
TABLE 17: TRANSMIT DATA LINK BYTE COUNT REGISTER (TDLBCR1)
HEX ADDRESS: 0Xn114
BIT
FUNCTION
TYPE DEFAULT
DESCRIPTION-OPERATION
7 TxHDLC1 BUFAvail/
R/W
BUFSel
0
Transmit HDLC1 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 HDLC1 Controller to read out and trans-
mit the data, residing within “Transmit HDLC1 Buffer # 0", via the
Data Link channel to the remote terminal equipment.
1 - Configures the Transmit HDLC1 Controller to read out and trans-
mit the data, residing within the “Transmit HDLC1 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 HDLC1 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 HDLC1 Mes-
sage Buffer, he/she should proceed to write this message into
“Transmit HDLC1 Buffer # 0" - Address location: 0xn600.
1 - Indicates that “Transmit HDLC1 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 HDLC1 Mes-
sage Buffer, he/she should proceed to write this message into
“Transmit HDLC1 Buffer # 1" - Address location: 0xn700.
NOTE: If one of these Transmit HDLC1 buffers contain a message
which has yet to be completely read-in and processed for
transmission by the Transmit HDLC1 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 HDLC1 Message - Byte Count
The exact function of these bits depends on whether the Transmit
HDLC 1 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 HDLC1 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.
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