IDT82V2082 Integrated Device Technology, Inc., IDT82V2082 Datasheet - Page 18

• Manufacturer Part Number: IDT82V2082
• Description: 2Ch T1/J1/E1 Short Haul/long Haul Liu
• Manufacturer: Integrated Device Technology, Inc.

DUAL CHANNEL T1/E1/J1 LONG HAUL/SHORT HAUL LINE INTERFACE UNIT
the T1.102 and the measuring diagram is shown in Figure-6. This also
meets the requirement of G.703, 2001. The cable length is divided into five
grades, and there are five pulse templates used for each of the cable length.
The pulse template is selected by PULS[3:0] bits (TCF1, 05H...).
‘0111’.
3.3.3.2 LBO (Line Build Out)
could be attenuated before transmission for long haul applications. The
FCC Part 68 Regulations specifies four grades of attenuation with a step
of 7.5 dB. Three LBOs are used to implement the pulse attenuation. The
PULS[3:0] bits (TCF1, 05H...) are used to select the attenuation grade. Both
Table-14
Note: 1. For R
Note: R
For T1 applications, the pulse shape is shown in
For J1 applications, the PULS[3:0] (TCF1, 05H...) should be set to
To prevent the cross-talk at the far end, the output of TTIPn/TRINGn
IDT82V2082
-0.2
-0.4
-0.6
1.2
0.8
0.6
0.4
0.2
2. For R
1
0
Table-14
LOAD
IDT82V2082
0
Figure-4 E1 Pulse Template Test Circuit
Figure-6 T1 Pulse Template Test Circuit
and
Figure-5 DSX-1 Waveform Template
= 100 Ω ± 5%
LOAD
LOAD
Table-15
lists these values.
= 75 Ω (nom), V
=120 Ω (nom), V
TTIPn
TRINGn
250
TTIPn
list these values.
TRINGn
out
500
out
(Peak)=2.37V (nom)
(Peak)=3.00V (nom)
Time (ns)
750
Cable
Figure-5
R
LOAD
1000
R
according to
LOAD
V
OUT
V
OUT
1250
18
3.3.3.3 User-Programmable Arbitrary Waveform
waveform generator mode can be used in the corresponding channel. This
allows the transmitter performance to be tuned for a wide variety of line con-
dition or special application.
UI[1:0] bits (TCF3, 07H...) and each UI is divided into 16 sub-phases,
addressed by the SAMP[3:0] bits (TCF3, 07H...). The pulse amplitude of
each phase is represented by a binary byte, within the range from +63 to -
63, stored in WDAT[6:0] bits (TCF4, 08H...) in signed magnitude form. The
most positive number +63 (D) represents the maximum positive amplitude
of the transmit pulse while the most negative number -63 (D) represents the
maximum negative amplitude of the transmit pulse. Therefore, up to 64
bytes are used. For each channel, a 64 bytes RAM is available.
User can select one of them as reference and make some changes to get
the desired waveform.
pulse shape. In order to do this, firstly, users can choose a set of waveform
value from the following twelve tables, which is the most similar to the
desired pulse shape. Table-2, Table-3, Table-4, Table-5, Table-6, Table-7,
Table-8, Table-9, Table-10, Table-11,
data and scaling data of each of the twelve templates. Then modify the cor-
responding sample data to get the desired transmit pulse shape.
by 1, the pulse amplitude can be scaled up or down at the percentage ratio
against the standard pulse amplitude if needed. For different pulse shapes,
the value of SCAL[5:0] bits and the scaling percentage ratio are different.
The following twelve tables list these values.
grammed, based on the selected waveform template:
from the internal RAM.
lap of two consecutive pulses could make the pulse amplitude overflow
(exceed the maximum limitation) if the pulse amplitude is not set properly.
This overflow is captured by DAC_OV_IS bit (INTS1, 19H...), and, if
enabled by the DAC_OV_IM bit (INTM1, 14H...), an interrupt will be gen-
erated.
There are twelve standard templates which are stored in an on-chip ROM.
When the PULS[3:0] bits are set to ‘11xx’, user-programmable arbitrary
Each pulse shape can extend up to 4 UIs (Unit Interval), addressed by
User can change the wave shape and the amplitude to get the desired
Secondly, through the value of SCAL[5:0] bits increased or decreased
Do the followings step by step, the desired waveform can be pro-
(1).Select the UI by UI[1:0] bits (TCF3, 07H...)
(2).Specify the sample address in the selected UI by SAMP [3:0] bits
(3).Write sample data to WDAT[6:0] bits (TCF4, 08H...). It contains the
(4).Set the RW bit (TCF3, 07H...) to ‘0’ to implement writing data to RAM,
(5).Implement the Read from RAM/Write to RAM by setting the DONE
Repeat the above steps until all the sample data are written to or read
(6).Write the scaling data to SCAL[5:0] bits (TCF2, 06H...) to scale the
When more than one UI is used to compose the pulse template, the over-
(TCF3, 07H...)
data to be stored in the RAM, addressed by the selected UI and the
corresponding sample address.
or to ‘1’ to implement read data from RAM
bit (TCF3, 07H...)
amplitude of the waveform based on the selected standard pulse
amplitude
Table-12
TEMPERATURE RANGES
and
Table-13
INDUSTRIAL
list the sample