PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 150

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

Semiconductor Group
RES
RES1
SSP
UAR
Pins
Pin-RES
Pin-SSP
Pin-DT
Reset
Unconditional command which resets the transceiver core (see "Reset
Behavior", page 94). For cold start the reset code should be applied for a
period of at least 8 IOM
needs to be applied during reset.
Reset 1
The reset 1 command resets all Receiver functions; especially the EC- and
EQ-coefficients and the AGC are set to zero. It resets also the awake signal
detection. The RES1-code does not reset IOM
Channel procedure or power controller interface). The RES1-code should
be used when the IEC-Q has entered a failure condition (expiry of timer T1,
loss of framing or loss of signal level) indicated by the C/I-channel EI3, RSY
or LSL on DOUT. Besides resetting the Receiver, this command stops
transmission on the U-interface. The DEA bit is not set to "0" by RES1.
Send Single Pulses
Unconditional command which requests the transmission of single pulses
on the U-interface. The pulses are issued at 1.5 ms intervals and have a
duration of 12.5 s.
The chip is transferred to the "Test" state; the Receiver will not be reset.
Partial Activation Request (U only)
The IEC-Q is requested to enter power-up state and to start an activation
procedure of the U-interface only.
Pin-Reset
Corresponds to a low level at pin RES. Resets the transceiver core and all
registers except for register STCR in the microprocessor mode (see "Reset
Behavior", page 94). The C/I-message DEAC will be issued. The duration of
the reset pulse must be 30 ns minimum. The reset will be carried out only
after the IOM
Pin-Send Single Pulses
Applies only in stand-alone mode. Corresponds to a high level at pin TSP.
The function of this pin is the same as for the C/I-code SSP. The
C/I-message DEAC will be issued. The high level needs to be applied
continuously for the transmission of single pulses.
Pin-Data Through
Applies only in stand-alone mode. Entered when both RES and TSP are
active (RES = "0" and TSP = "1"). The function is identical with the C/I-code
DT.
®
-2 clocks are issued.
®
-2-frames (1 ms). In LT modes the DCL clock signal
150
®
Operational Description
-2-functions (e.g. Monitor
Data Sheet 01.99
PEB 2091
PEF 2091