pef22504 Infineon Technologies Corporation, pef22504 Datasheet - Page 92

• 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

•
If a loss-of-signal condition is detected in long-haul mode, the data stream can optionally be cleared automatically
to avoid bit errors before LOS is indicated. The Selection is done by LIM1.CLOS = ´1´.
3.7.5
The QuadLIU
E1 or -36 dB for T1/J1. The maximum reachable length with a 22 AWG twisted pair cable is about 1500 m for E1
and about 2000m (~6560 ft) for T1. The integrated receive equalization network recovers signals with up to -43
dB for E1 or -36 dB for T1/J1 of cable attenuation automatically. Noise filters eliminate the higher frequency part
of the received signals. The incoming data is peak-detected and sliced to produce the digital data stream. The
slicing level is software selectable in four steps (45%, 50%, 55%, 67%), see
a level of 50% is used. The received data is then forwarded to the clock & data recovery unit.
3.7.6
Status register RES reports the current receive line attenuation
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•
The least significant 5-bits of this register indicate the cable attenuation in dB. These 5-bits are only valid in
combination with the most significant two bits (RES.EV(1:0) = ´01
3.7.7
The analog received signal on pins RL1 and RL2 is equalized and then peak-detected to produce a digital signal.
The digital received signal on pins RDIP and RDIN is directly forwarded to the clock & data recovery. The so called
DPLL (digital PLL) of the receive clock & data recovery extracts the route clock from the data stream received at
the RL1/2 or ROID lines. The clock & data recovery converts the data stream into a dual-rail, unipolar bit stream.
The clock and data recovery uses an internally generated high frequency clock out of the master clocking unit
based on MCLK.
The intrinsic jitter generated in the absence of any input jitter is not more than 0.035 UI.
3.7.8
The receive jitter attenuator is based on the DCO-R (digital clock oscillator, receive) in the receive path. Jitter
attenuation of the received data is done in the dual receive elastic buffer. The working clock is an internally
generated high frequency clock based on the clock provided on pin MCLK. The jitter attenuator meets the E1
requirements of ITU-T I.431, G. 736 to 739, G.823 and ETSI TBR12/13 and the T1 requirements of AT&T
PUB 62411, PUB 43802, TR-TSY 009,TR-TSY 253, TR-TSY 499 and ITU-T I.431, G.703 and G. 824.
The internal PLL circuitry DCO-R generates a "jitter-free" output clock which is directly dependent on the phase
difference of the incoming clock and the jitter attenuated clock. The receive jitter attenuator can be synchronized
either on the extracted receive clock RCLK or on a 2.048 MHz/8 kHz or 1.544 MHz/8 kHz clock provided on pin
SYNC (8 kHz in master mode only). The jitter attenuated DCO-R output clock can be output on pin RCLK and
FCLKR. Optionally an 8 kHz clock is provided on pin SEC FSC.
For jitter attenuation the received data is written into the receive elastic buffer with the recovered clock sourced by
the clock & data recovery and are read out with the de-jittered clock sourced by DCO-R.
If the receive elastic buffer is read out directly with the recovered receive clock, no jitter attenuation is performed.
If the receive elastic buffer is read out with the receive framer clock FCLKR, the receive elastic buffer performs a
clock adoption from the recovered receive clock to FCLKR.
Data Sheet
periods. ETS300233 requires detection intervals of at least 1 ms. This time period results always in a LFA
(Loss of Frame Alignment) before a LOS is detected.
Recovery: In general the recovery procedure starts after detecting a logical one (digital receive interface) or a
pulse (analog receive interface) with an amplitude more than Q dB (defined by LIM1.RIL(2:0)) of the nominal
pulse. The value in the 8-bit register PCR defines the number of pulses (1 to 255) to clear the LOS alarm.
For E1 in a range from 0 to -43 dB in 25 steps of approximately 1.7 dB each.
For T1/J1 in a range from 0 to -36 dB in 25 steps of approximately 1.4 dB each.
Receive Equalization Network
Receive Line Attenuation Indication
Receive Clock and Data Recovery
Receive Jitter Attenuator
TM
automatically recovers the signals received on pins RL1 and RL2 in a range of up to -43 dB for
92
b
´).
Table
56. For typical E1 applications,
Functional Description
Rev. 1.3, 2006-01-25
QuadLIU
PEF 22504
TM