PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 160

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

Semiconductor Group
Test
This "Test" mode is entered when the unconditional commands RES, SSP, LTD,
Pin-RES, Pin-SSP or PFOFF are used. It is left when the pins RESQ, TSP and PS1 are
inactive and the C/I-channel code DR is received. The output signals are as follows:
– When the C/I-channel code RES or RES1 is applied or when the pin RESQ is
– When the C/I-channel code SSP is applied or when the pin TSP is activated:
– When the C/I-channel code LTD is applied:
– When the pin PS1 is activated:
In this state the IEC-Q does not react to the receipt of a wake-up signal TN.
Transparent
This "Transparent" state corresponds to the fully active state in the case of a normal
activation for call control. It may also be entered in the case of a loop-back 2 if the NT
issues ACT = 1 or in case of a single-channel loop-back in the NT. The LT side is
informed that the status "ready for sending" is reached (indication AI). If the NT side
loses transparency (receipt of ACT = 0), the LT side is informed by making use of the
C/I-channel indication EI2, but no state change is performed. If the S/T-interface is
deactivated (SAI = (0) & ACT = (0)), the device is transferred to the S/T deactivated state.
Wait for TN
In "Wait for TN" the IEC-Q waits for a response (tone TN from the NT or tone TL in case
of an analog loop-back) to the transmission of the wake-up signal TL. If no response is
received within T3, the state is left for re-transmission of a wake-up tone TL. This
procedure is repeated until the detection of tone TN or until expiry of timer T1. In this
case the C/I-channel indication EI3 is issued, but no state change is performed.
4.4.3
This chapter describes the behavior of the IEC-Q device if operated in either of the
following NT modes:
– NT mode (512 kHz)
– NT-PBX mode (512 – 4096 kHz)
– TE mode (1536 kHz)
– NT-Auto Activation mode (512 kHz)
Figure 73 describes the behavior of the first three modes, and Figure 74 describes the
behavior of the last one.
activated:
SL0 and DEAC
single pulses (SP) and DEAC
SL0 and DEAC; furthermore, the pin DISS is activated
SL0 and HI
State Machine in NT Modes
160
Operational Description
Data Sheet 01.99
PEB 2091
PEF 2091