82V2082PF IDT, Integrated Device Technology Inc, 82V2082PF Datasheet - Page 21

• Manufacturer Part Number: 82V2082PF
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of 82V2082PF

• 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: Not Compliant

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
FUNCTIONAL DESCRIPTION
IDT82V2082
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
Table-12
and
Table-13
DUAL CHANNEL T1/E1/J1 LONG HAUL/SHORT HAUL LINE INTERFACE UNIT
list the sample
21
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.
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
May 4, 2009