PEB 2091
PEF 2091
Operational Description
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" (0H)
• Read the CIRU register after receiving the ISTA:CICU interrupt and verify that the C/I
code "PU" (7H) has been indicated
• Write the C/I-command "AR" (8H) in combination with setting the SPU bit to "1" in the
CIWU register
4.3.15
Upstream Wake-Up Indication in the LT Repeater Mode
In repeater applications the IOM®-2 clocks are usually delivered by the NT repeater (see
"Repeater Modes", page 87). In power down the IOM®-2 clock will be shut down. During
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®-21). In the Deactivated state of the LT Repeater mode the pin DOUT will be
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)2). This allows
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.
.
Clamp to "0"
IEC-Q
IEC-Q
LT-RP
NT-RP
10 kHz
wake up tone
DIN
DOUT
DU
U
U
interface
interface
Upstream
Figure 70
Wake Up Indication in Repeater Power Down
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
NT repeater mode. Refer to "NT Repeater", page 88
2) To achieve this, all Monitor Channel commands and indications of the LT Repeater should be completed
before the NT Repeater enters the power down state
Semiconductor Group
143
Data Sheet 01.99
INFINEON [ Infineon ]
