PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 143

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

To activate the IEC-Q in NT mode from power down without external control of the pin
DIN the following procedure has to be used:
• Set the SPU bit to "0" in the CIWU-register (see "CIWU-Register", page 217)
• Write C/I-command "TIM" (0
• Read the CIRU register after receiving the ISTA:CICU interrupt and verify that the C/I
• Write the C/I-command "AR" (8
4.3.15
In repeater applications the IOM
"Repeater Modes", page 87). In power down the IOM
power down the reception of a wake up tone from downstream will therefore not be
indicated on C/I Channel in upstream direction.
The IEC-Q is equipped with an internal wake up detection function which doesn’t depend
on IOM
clamped to "0" if a wake-up tone from down stream is detected and if no Monitor Channel
command is active or pending (in both up and down stream directions)
connecting pin DOUT of the LT repeater directly to pin DIN of the NT repeater, and
activation initiated by the TE will be carried out without restrictions, as Figure 70 below
and the example thereafter show.
.
Figure 70
1) Note that the 15.36 MHz master clock will still be required. Version 5.3 provides such a clock on pin CLS in the
2) To achieve this, all Monitor Channel commands and indications of the LT Repeater should be completed
Semiconductor Group
code "PU" (7
CIWU register
NT repeater mode. Refer to "NT Repeater", page 88
before the NT Repeater enters the power down state
wake up tone
®
-2
10 kHz
1)
Upstream Wake-Up Indication in the LT Repeater Mode
. In the Deactivated state of the LT Repeater mode the pin DOUT will be
Wake Up Indication in Repeater Power Down
H
) has been indicated
interface
U
H
®
)
-2 clocks are usually delivered by the NT repeater (see
H
LT-RP
IEC-Q
) in combination with setting the SPU bit to "1" in the
DOUT
143
Clamp to "0"
Upstream
DU
®
-2 clock will be shut down. During
DIN
NT-RP
IEC-Q
Operational Description
interface
Data Sheet 01.99
2)
U
. This allows
PEB 2091
PEF 2091