xr
PRELIMINARY
XRT86VL38
REV. P1.0.6
OCTAL T1/E1/J1 FRAMER/LIU COMBO
378
X
Y
: The Xth payload bit of Channel Y
A
Y
: The signaling bit A of Channel Y
5.
After payload bits of Timeslot 0, 1 and 2 of all four channels are sent, the Terminal Equipment should stuff
another eight octets (sixty-four bits) of "don't care" data into the outgoing data stream.
6.
Following the same rules of Step 2 to 5, the local Terminal Equipment stuffs eight octets of "don't care" data
after sending twenty-four octets of multiplexed payload and signaling data. A 16.384Mbit/s data stream is
thus created.
The Transmit Single-frame Synchronization signal of Channel 0 pulses HIGH for one clock cycle at the first bit
position (F-bit of channel 0) of the data stream with data from Channel 0-3 multiplexed together. The Transmit
Single-frame Synchronization signal of Channel 4 pulses HIGH for one clock cycle at the first bit position (F-bit
of Channel 4) of the data stream with data from Channel 4-7 multiplexed together. By sampling the HIGH pulse
on the Transmit Single-frame Synchronization signal, the framer can position the beginning of the multiplexed
DS1 frame. It is responsibility of the Terminal Equipment to align the multiplexed transmit serial data with the
Transmit Single-frame Synchronization pulse.
Inside the framer, all the "don't care" bits will be stripped away. The framing bits, signaling and payload data are
de-multiplexed inside the XRT86VL38 and send to each individual channel. These data will be processed by
each individual framer and send to LIU interface. The local Terminal Equipment provides a free-running
1.544MHz clock to the Transmit Serial Input clock of each channel. The framer will use this clock to carry the
processed payload and signaling data to the transmit section of the device.
Figure shows the timing signal when the transmit framer is running at 16.384 Bit-Multiplexed mode.
Transmit HMVIP / H.100 Byte-Multiplexed mode at 16.384 MHz
Please refer to Figure 91 for how to interface the transmit payload data input interface block to the terminal
equipment. The local Terminal Equipment maps four 1.544Mbit/s DS1 data streams into this 16.384Mbit/s data
stream as described below:
1.
The F-bit of four channels are repeated and grouped together to form the first octet of the multiplexed data
stream. The F-bit of Channel 0 is sent first, followed by F-bit of Channel 1 and 2. The F-bit of Channel 3 is
sent last. The table below shows bit-pattern of the first octet.
F
X
: F-bit of Channel X
2.
After the first octet of data is sent, the local Terminal Equipment should insert seven octets (fifty-six bits) of
"don't care" data into the outgoing data stream.
3.
Payload data of four channels are repeated and grouped together in a byte-interleaved way. The first pay-
load bit of Timeslot 0 of Channel 0 is sent first, followed by the second payload bit of Timeslot 0 of Channel
0 and so on. After all the bits of Timeslot 0 of Channel 0 is sent repeatedly, the Terminal Equipment will
start sending the payload bits of Timeslot 0 of Channel 1 and 2. The payload bits of Timeslot 0 of Channel
3 are sent the last. After the payload bits of Timeslot 0 of all four channels are sent, it comes the payload
F
IGURE
93. T
IMING
SIGNALS
WHEN
THE
TRANSMIT
FRAMER
IS
RUNNING
AT
16.384 B
IT
-M
ULTIPLEXED
MODE
B
IT
0
B
IT
1
B
IT
2
B
IT
3
B
IT
4
B
IT
5
B
IT
6
B
IT
7
F
0
F
0
F
1
F
1
F
2
F
2
F
3
F
3
TxInClk (16.384MHz)
TxInClk (INV)
TxSer
TxSync(input)
F
0
F
0
F
1
F
1
F
2
F
2
F
3
F
3
1
0
X 1
1
X
X
X
1
2
1
3
2
0
X 2
1
X
X
3
0
4
0
X
5
0
A
0
5
1
A
1
5
2
A
2
5
3
A
3
56 cycles
