PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 145

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

4.4
4.4.1
The state machine includes all information necessary for the user to understand and
predict the activation/deactivation status of the IEC-Q. The information contained in a
state bubble is:
– State name
– U-signal transmitted
– Overhead bits transmitted
– C/I-code transmitted
– Transition criteria
– Timers
Figure 71
The following example explains the use of a state diagram by an extract of the LT state
diagram. The state explained is the "Deactivated" state in LT mode.
The state may be entered by either of three methods:
– From state "Receive Reset" after time T7 has expired (T7 E xpired )
– From state "Tear Down" after the internal transition criterion "LSU" is fulfilled
– From state "Test" after the C/I-command "DR" has been sent downstream
The following information is transmitted:
– SL0 is sent on the U-interface (no signal, see "U-Interface Signals", page 125)
– No overhead bits are sent
– C/I-message "DI" is issued on upstream
The state may be left by either of the following methods:
Semiconductor Group
State Machines
State Machine Notation Rules
State Diagram Notation
Signal Transmitted
to U-Interface
Indication Transmitted on C/I-Channel
(general)
State Name
145
(DD)
OUT
IN
to U-Interface
Transmitted
Single Bit
ITD04257
Operational Description
Data Sheet 01.99
PEB 2091
PEF 2091