PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 165

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

µP-SSP
µP-DT
U-Interface Events
The signals SLx and TL received on the U-interface are defined in Table 28, page 125.
ACT
DEA
UOA
LOF
LSEC
Semiconductor Group
µP-Send Single Pulses
Applies only in microprocessor mode. Corresponds to the setting:
STCR:TM1 = ’1’ and STCR:TM2 = ’1’. The function of this setting is the
same as of the C/I-code SSP. C/I-message DR will be issued. See "Test
Modes", page 52.
µP-Data Through
Applies only in microprocessor mode. This function is activated by setting:
STCR:TM1 = ’0’ and STCR:TM2 = ’1’. The function of this setting is the
same as of the C/I-code DT. See "Test Modes", page 52.
ACT-bit received from LT side.
– ACT = 1 requests the IEC-Q to transmit transparently in both directions.
– ACT = 0 indicates that the LT side has lost transparency.
DEA-bit received from the LT side
– DEA = 0 informs the IEC-Q that a deactivation procedure has been
– DEA = 1 reflects the case when DEA = 0 was detected by faults due to
UOA-bit received from network side
– UOA = 0 informs the IEC-Q that only the U-interface is to be activated.
– UOA = 1 enables the S/T-interface to activate.
Loss of Framing on the U-interface
This condition is fulfilled if framing is lost for 576 ms. 576 ms are the upper
limit. If the correlation between synchronization word and the input signal is
not optimal, LOF may be issued earlier.
Loss of Signal level behind the Echo Canceler
Internal signal which indicates that the echo canceler has converged.
As transparency in receive direction (U-interface to IOM
performed when the Receiver is synchronized, the receipt of ACT = 1
establishes transparency in transmit direction (IOM
too. In the case of loop-backs, however, transparency in both directions
of transmission is established when the Receiver is synchronized.
started by the LT side.
e.g. transmission errors and allows the IEC-Q to recover from this
situation (see state ’Pend. Deact. U’).
The S/T-interface must remain deactivated.
165
Operational Description
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-2 to U-interface),
Data Sheet 01.99
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PEB 2091
PEF 2091