peb2256 Infineon Technologies Corporation, peb2256 Datasheet - Page 361

• 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 Registers (Read/Write)
Value after reset: 7B
XPM0
XPM1
XPM2
The transmit pulse shape which is defined in ANSI T1.102 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.
The XPM values in the following table are based on simulations. They are valid for the
following external circuitry: transformer ratio 1:2.4, cable PULB 22AWG (100 Ω ), serial
resistors 2 Ω . Adjustment of these coefficients can be necessary for other external
conditions.
Table 64
Range in
m
0 to 40
40 to 81
81 to 122
122 to 162 399 to 533 5F
162 to 200 533 to 655 3F
Data Sheet
XP12
XP30
7
0
Range in
ft.
0 to 133
133 to 266 FA
266 to 399 3D
Pulse Shaper Programming (T1/J1)
XP04 to 00:
XP14 to 10:
XP24 to 20:
XP34 to 30:
XP11
XP24
XLT
H
, 03
XPM0
D7
H
, 40
DAXLT
XP10
XP23
H
hexadecimal
First pulse shape level
Second pulse shape level
Third pulse shape level
Fourth pulse shape level
XPM1
22
26
37
3F
CB
XP04
XP22
361
XPM2
1
1
1
1
1
XP03
XP21
XP34
XP04-
XP00
23
26
29
31
31
XP02
XP20
XP33
XP14-
XP10
22
23
25
26
25
XP01
XP14
XP32
decimal
T1/J1 Registers
XP24-
XP20
8
9
13
15
18
FALC56 V1.2
XP00
XP13
XP31
0
PEB 2256
2002-08-27
XP34-
XP30
2
2
2
2
3
(26)
(27)
(28)