82V2081PPG8 IDT, Integrated Device Technology Inc, 82V2081PPG8 Datasheet - Page 16

• Manufacturer Part Number: 82V2081PPG8
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of 82V2081PPG8

• Number Of Transceivers: 1
• Screening Level: Industrial
• Mounting: Surface Mount
• Package Type: TQFP
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Lead Free Status / RoHS Status: Compliant

SINGLE 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, 06H).
Table-14
3.3.3.2 LBO (Line Build Out)
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, 06H) are used to select the attenuation grade. Both
and
Note: 1. For R
For T1 applications, the pulse shape is shown in
For J1 applications, the PULS[3:0] (TCF1, 06H) should be set to ‘0111’.
To prevent the cross-talk at the far end, the output of TTIP/TRING could
Note: R
Table-15
IDT82V2081
-0.2
-0.4
-0.6
1.2
0.8
0.6
0.4
0.2
1
0
2. For R
0
IDT82V2081
Figure-4 E1 Pulse Template Test Circuit
Figure-6 T1 Pulse Template Test Circuit
lists these values.
LOAD
Figure-5 DSX-1 Waveform Template
= 100 Ω ± 5%
list these values.
LOAD
LOAD
= 75 Ω (nom), V
=120 Ω (nom), V
TRING
TTIP
250
TTIP
TRING
500
out
out
(Peak)=2.37V (nom)
(Peak)=3.00V (nom)
Time (ns)
750
Cable
Figure-5
R
LOAD
1000
R
according to
LOAD
V
Table-14
OUT
V
1250
OUT
16
3.3.3.3 User-Programmable Arbitrary Waveform
waveform generator mode can be used. This allows the transmitter perfor-
mance to be tuned for a wide variety of line condition or special application.
UI[1:0] bits (TCF3, 08H) and each UI is divided into 16 sub-phases,
addressed by the SAMP[3:0] bits (TCF3, 08H). 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, 09H) in signed magnitude form. The most
positive number +63 (D) represents the positive maximum amplitude of the
transmit pulse while the most negative number -63 (D) represents the max-
imum negative amplitude of the transmit pulse. Therefore, up to 64 bytes
are used.
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, 1AH), and, if enabled
by the DAC_OV_IM bit (INTM1, 15H), an interrupt will be generated.
templates and LBOs in detail for reference. For preset pulse templates and
LBOs, scaling up/down against the pulse amplitude is not supported.
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, 08H)
(2).Specify the sample address in the selected UI by SAMP [3:0] bits
(3).Write sample data to WDAT[6:0] bits (TCF4, 09H). It contains the
(4).Set the RW bit (TCF3, 08H) 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, 07H) to scale the
When more than one UI is used to compose the pulse template, the over-
The following tables give all the sample data based on the preset pulse
(TCF3, 08H)
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, 08H)
amplitude of the waveform based on the selected standard pulse
amplitude
Table-12
TEMPERATURE RANGES
and
Table-13
INDUSTRIAL
list the sample