PEB2085 SIEMENS [Siemens Semiconductor Group], PEB2085 Datasheet - Page 173

• Manufacturer Part Number: PEB2085
• Description: ISDN SubscribernAccess Controller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Operational Description
F3 Power Down
This is the deactivated state of the physical protocol. The receive line awake unit is active
except during an RST pulse. Clocks are disabled if ADF1/SQXR:CFS=1 (TE mode). The
power consumption in this state is approximately 80 mW when the clock is running, and 8 mW
otherwise.
F3 Power Up
This state is identical to "F3 power down", except for the C/I output message. The state is
invoked by a C/I command TIM = "0000" (or IDP1 static low). After the subsequent activation
of the clocks the PU message is outputted. This occurs 0.5 ms to 4 ms after application of TIM,
depending on crystal capacitances. If, however, the ISAC-S is disconnected from the S
interface (CON = 0), the C/I message DIS is outputted.
F3 Pending Deactivation
The ISAC-S reaches this state after receiving INFO0 (from states F5 to F8) for 16 ms
(64
frames). This time constant is a "flywheel" to prevent accidental deactivation. From this state
an activation is only possible from the line (transition "F3 pend. deact." to "F5
unsynchronized"). A power down state may be reached only after receiving DIU.
F4 Pending Activation
Activation has been requested from the terminal, INFO1 is transmitted, INFO0 is still received,
"Power Up" is transmitted in the C/I channel. This state is stable: timer T3 (I.430) is to be
implemented in software.
F5 Unsynchronized
At the reception of any signal from the NT, the ISAC-S ceases to transmit INFO1 and awaits
identification of INFO2 or INFO4. This state is reached at most 50 s after a signal different
from INFO0 is present at the receiver of the ISAC-S.
F6 Synchronized
When the ISAC-S receives an activation signal (INFO2), it responds with INFO3 and waits for
normal frames (INFO4). This state is reached at most 6 ms after an INFO2 arrives at the ISAC-
S (when the oscillator was disabled in "F3 power down").
F7 Activated
This is the normal active state with the layer-1 protocol activated in both directions. Note that
in IOM-2 mode the 2B+D channels can only be transmitted to the SIT interface if an "Activation
Request" command is written to the CIX0 register. From state "F6 synchronized", state F7 is
reached at most 0.5 ms after reception of INFO4. From state "F3 power down" with the
oscillator disabled, state F7 is reached at most 6 ms after the ISAC-S is directly activated by
INFO4.
Semiconductor Group
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