pef22504 Infineon Technologies Corporation, pef22504 Datasheet - Page 85

• Manufacturer Part Number: pef22504
• Description: Quad E1/t1/j1 Line Interface Component For Long- And Short-haul Applications Pef 22504 E, Pef 22504 Ht, Version 2.1
• Manufacturer: Infineon Technologies Corporation

applications. Closing of the separate analog switches if its connectors RLAS2(1:4) are connected to VSSX
the device might get demaged.
It is also possible to control both switches by using a combination of both hardware and software using one (but
not more) of the receive Multi Function Ports as a Receive Line Termination (RLT) input.
It is proposed that the Multi Function Port RPB be used for the RLT input, if this is the case then the
PC2.RPC2(3:0) register bits must be programed to ´1000
If RLT is configured at one of the Multi Function Ports, the R
(LIM0.RTRS == RLT) & LIM2.MPAS and the analog switch is controlled by the logical function LIM0.RTRS ==
RLT, were “==” means logical equivalence.
This enables a simple redundancy application using only one common board signal for switching between two
channels. While one channel terminates the receive line with an impedance matched to the line impedance Z
other channel is in high impedance mode (both switches are óff´).
Table 14
Table 14
300 Ohm
Switch
off
off
on
on
1) Because makes no sense for redundancy applications
Figure 24
This type of control offers very flexible receiver configurations which are described in the next chapters:
3.7.3.1
A “generic” receiver configuration, using the same resistor R
impedances Z
Data Sheet
shows the controlling of the switches (if GPC(3:6).ENMPAS = ´1111
Controlling of the Receive Interface Switches
General Receiver Configuration with Integrated Resistor and Analog Switches for Receive
Impedance Matching
“Generic” Receiver Interface
0
Z
, is shown in
0
Analog
Switch
off
on
off
on
externally
Table
15.
RLT is not Configured
LIM0.RTRS
0
0
1
1
R
S
R
E
LIM2.MPAS
1
0
1
RL1
RL2
RLAS2
0
85
b
´, see
TERM
internally
E
= 300
Table
= 100
R
QLIU_analog_switches_1
RLT is Configured
LIM0.RTRS == RLT LIM2.MPAS
0
1
Not applicable
1
34.
TERM
switch is controlled by the logical function
for all applications with different line
b
´).
1)
Functional Description
Rev. 1.3, 2006-01-25
0
1
X
QuadLIU
PEF 22504
0
, the
TM