peb2256 Infineon Technologies Corporation, peb2256 Datasheet - Page 241

• Manufacturer Part Number: peb2256
• Description: E1/t1/j1 Framer And Line Interface Component For Long And Short Haul Applications
• Manufacturer: Infineon Technologies Corporation

Transmit Pulse Mask (Read/Write)
Value after reset: 7B
XPM0
XPM1
XPM2
The transmit pulse shape which is defined in ITU-T G.703 is output on pins XL1 and XL2.
The level of the pulse shape can be programmed by registers XPM(2:0) to create a
custom waveform. In order to get an optimized pulse shape for the external transformers
each pulse shape is internally divided into four sub pulse shapes. In each sub pulse
shape a programmed 5 bit value defines the level of the analog voltage on pins XL1/2.
Together four 5 bit values have to be programmed to form one complete transmit pulse
shape. The four 5 bit values are sent in the following sequence:
Changing the LSB of each subpulse in registers XPM(2:0) changes the amplitude of the
differential voltage on XL1/2 by approximately 80 mV.
Example:120 Ω interface and wired as shown in
Programming values for XPM(2:0): 00
XLT
Data Sheet
XP12
XP30
7
0
XP04 to 00:
XP14 to 10:
XP24 to 20:
XP34 to 30:
XP04 to 00:
XP14 to 10:
XP24 to 20:
XP34 to 30:
Transmit Line Tristate
0 =
1 =
XP11
XP24
XLT
H
, 03
Normal operation
Transmit line XL1/XL2 or XDOP/XDON are switched into high-
impedance state. If this bit is set the transmit line monitor status
information is frozen (default value after hardware reset).
H
, 40
DAXLT
XP10
XP23
H
First pulse shape level
Second pulse shape level
Third pulse shape level
Fourth pulse shape level
1B
1B
00
00
H
H
H
H
XP04
XP22
or 27 decimal
or 27 decimal
H
, 03
241
H
,7B
XP03
XP21
XP34
H
Figure 50
XP02
XP20
XP33
on
page
XP01
XP14
XP32
155.
FALC56 V1.2
XP00
XP13
XP31
E1 Registers
0
PEB 2256
2002-08-27
(26)
(27)
(28)