XRT84L38 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT84L38' PDF : 453 Pages View PDF
REV. 1.0.1
XRT84L38
OCTAL T1/E1/J1 FRAMER
BIT NUMBER
BIT NAME
BIT TYPE
BIT DESCRIPTION
5-4
Transmit Data Link Band- R/W Transmit Data Link Bandwidth Select:
width Select
These READ/WRITE bit-fields determined the bandwidth of
Facility Data Link channel of the framer when operating in ESF
mode.
When these bits are set to 00:
The Facility Data Link is a 4KHz channel. All available FDL bits
(first bit of every other frame) are used as data link bits.
When these bits are set to 01:
The Facility Data Link is a 2KHz channel. Only the odd FDL bits
(first bit of frame 1, 5, 9…) are used as data link bits.
When these bits are set to 10:
The Facility Data Link is a 2KHz channel. Only the even FDL bits
(first bit of frame 3, 7, 11…) are used as data link bits.
3-2
D/E Timeslot Source
Select
R/W D/E Timeslot Source Select:
These READ/WRITE bit-fields permit the user to select data
source of D or E channel (D/E Timeslot) for the ISDN Primary
Rate Interface, if LAPDSEL[1:0] bits in TCCR is 10.
NOTE:
The LAPD Select (LAPDSEL) bits of the Transmit
Channel Control Register (TCCR) determine which one
of the three LAPD channel are used for D/E timeslot. If
LAPDSEL[1:0] = 10, the D/E Timeslot Source Select bits
will determine the data source for D/E time slot.
The ISDN Primary Rate Interface (ISDN I.431) can carry B chan-
nel, D channel, E channel and H channel. B channel has a bit
rate of 64Kbit/s and is equivalent to a DS0 channel in T1 used
for payload transmission. D channel has a bit rate of 64Kbit/s
and is used primarily for signaling transmission. E channel has a
bit rate of 64Kbit/s and is used for signaling for circuit switching.
It is used only with multiple-access configuration. H channel has
bit rates of 384Kbit/s, 1536Kbit/s for T1 primary rate, and
1920Kbit/s for E1 primary rate.
The signaling information presented on D or E channels are pro-
vided by several sources. The user can provide the signaling
information through the Transmit Serial Data via the TxSer_n
pins. The user can also supply the signaling data by writing to
the LAPD controller using microprocessor access. Finally, the
user can provide the data through Fraction T1 input via the
TxFrT1_n pins.
When these bits are set to 00:
The D or E channel data are inserted from the Transmit Serial
Data input.
When these bits are set to 01:
The D or E channel data are inserted from the LAPD controllers.
The user can read or write to the LAPD controller using micro-
processor access.
When these bits are set to 10:
The D or E channel data are inserted from the Transmit Serial
Data input.
When these bits are set to 11:
The D or E channel data are inserted from the Fractional T1
input.
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