PEF22504HT datasheet(91/255 Pages) INFINEON

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Data Sheet

Rev. 1.3, 2006-01-25

QuadLIU

PEF 22504

Functional Description

In the first (“non-generic”) application only the analog switch is used. These switch is ´on´ in the active and ´off´ in

the stand-by channel. The 300

Ω switch is unused (always ´off´, register bit LIM2.MPAS of both channels is always

´0´). Also the transmit interface works in a non-generic mode (see Chapter 3.9.1): The register bit PC6.TSRE of

both channels is always ´0´. The configuration (additional to that of Table 19) is shown in Table 20:

In the generic redundancy application different line impedances Z

0 can be used without changing the board.

Additionally to the the analog switch the 300

Ω switch is used to match the termination resistance to the different

line impedances Z

0 (register bit LIM2.MPAS of both channels). In the active channel this switch is ´on´ if the line

impedance is 75

Ω and ´off´ otherwise. In the stand-by channel this switch is always óff´, see Table 22.

Also the transmit interface works in a generic mode (see Chapter 3.9.1) using the register bit PC6.TSRE of both

channels.

The configuration (additional to that of Table 19) is shown in Table 21:

Table 22 illustrates the switching in the receive path used in the “generic” redundancy application:

3.7.4

Loss-of-Signal Detection

There are different definitions for detecting Loss-Of-Signal (LOS) alarms in the ITU-T G.775 and ETS 300233. The

QuadLIU

TM covers all these standards. The LOS indication is performed by generating an interrupt (if not masked)

and activating a status bit. Additionally a LOS status change interrupt is programmable by using register GCR.SCI.

•

Detection: An alarm is generated if the incoming data stream has no pulses (no transitions) for a certain

number (N) of consecutive pulse periods. A pulse with an amplitude less than Q dB below nominal is the criteria

for “no pulse” in the analog receive interface (LIM1.DRS = ´0´) (LIM1). The receive signal level Q is

programmable by three control bits LIM1.RIL(2:0) see Table 56. The number N can be set by an 8-bit register

(PCD). The contents of the PCD register is multiplied by 16, which results in the number of pulse periods, i.e.

the time which has to suspend until the alarm has to be detected. The programmable range is 16 to 4096 pulse

Table 20

Configuration for “non-generic” Redundancy Applications, Switching with only one Board

Signal

Line Impedance Z

[Ohm]

S [Ohm]

SER [Ohm]

LIM2.MPAS

PC6.TSRE

120

5.5 or 0, see

Table 28

110

100

Table 21

Configuration for “generic” Redundancy Applications, Switching with only one Board Signal

Line Impedance Z

[Ohm]

S [Ohm]

SER [Ohm]

LIM2.MPAS

PC6.TSRE

120

0See Table 28

110

100

Table 22

Switching in “Generic” Redundancy Application

Channel

300 Ohm Switch

Analog Switch

Active channel

Off, if Z

0 is 120 Ω,110 Ω or 100 Ω (GPC1.MPAS = ´0´)

On, if Z

0 is 75 Ω (LIM2.MPAS = ´1´)

Stand-by channel

Off

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