PEB24901HV12 Lantiq, PEB24901HV12 Datasheet - Page 66

• Manufacturer Part Number: PEB24901HV12
• Manufacturer: Lantiq

Specifications of PEB24901HV12

• Lead Free Status / Rohs Status: Supplier Unconfirmed

4.10 Awake Signal Detection
To activate the Uk0 interface, special awake and acknowledge signals (INFO U1W and
U2W) are defined. The activating Quad IEC DFE-T sends out a 7.5 kHz tone of 2.133 ms
duration, which has to be detected by the IEC on the other end of the line, which then
acknowledges it with the same 7.5 kHz tone of 2.133 ms duration.
The awake/acknowledge signal is generated like each signal on the U link, but neither
4B3T coded data nor frames are transmitted. The awake/acknowledge signal is a series
of 16 periods. Each of them is generated by subsequent 8 plus-level and 8 minus-level
ternary symbols with the usual 120 kBaud symbol rate. During normal transmission no
such symbol sequence can occur.
A special awake unit is implemented in the Quad IEC DFE-T. After detecting a wake-up
signal, the control procedures are started (see section 3.4).
The line signal is evaluated by checking for level, frequency and duration. To be
recognized as valid, the wake-up signal has to exceed a threshold level of 25 - 80 mV at
the line side of the transformer, and its frequency has to be between 6.15 kHz as lower
limit and 8.27 - 8.89 kHz as higher limit. After detecting 14 subsequent rising edges on
the line within the frequency range, the Quad IEC DFE-T waits until no two subsequent
falling edges occur within a period of 0.39 ms which could belong to an awake signal.
This happens usually after the 16
occur.
Figure 28:
Level and Frequency for Awake Signal Recognition
Semiconductor Group
80 mV
20 mV
6.15 6.49
no awake signal detected
th
awake signal
edge when only some attenuated oscillations may
detected
65
8.27 8.89
PEB 24901
02.95