pef20550 Infineon Technologies Corporation, pef20550 Datasheet - Page 87

• Manufacturer Part Number: pef20550
• Description: Extended Line Card Interface Controller Elic
• Manufacturer: Infineon Technologies Corporation

2.2.8.3 Control Channel Delay
Depending on the selected system configuration different delays between the activation
of the control channel and the corresponding D-channel response occur.
Table 14
Control Channel Delay Examples
System
Configuration
U
- U
U
- S
- S
U
- U
- U
S
- S
Beware of Arbiter Locking!
In the state "limited selection", the D-channel arbiter sends the "blocked" information to
the terminal from which the last HDLC-frame was received. Since the "blocked"
information reaches the terminal with several IOM-frames delay
5
reception of the "blocked" information the terminal immediately aborts this frame.
Since the abort sequence of the second frame reaches the ELIC with several frames
delay
enters the state "full selection" only after the abort sequence of the second frame has
reached the ELIC.
If the D-channel arbiter re-enters the "full selection" state (in which it again sends an
"available" information to the terminal) before the abort sequence has reached the ELIC,
it would mistake a ’0’ of the second frame as the start of a new frame. When the delayed
abort sequence arrives at the ELIC, the D-channel arbiter would then switch back to the
state "limited selection" and re-block the terminal. Thus the D-channel arbiter would
toggle between sending "available" and "blocked" information to the terminal, forever
aborting the terminal‘ s frame. The arbiter would have locked.
Semiconductor Group
0
PN
PN
PN
0
0
0
PN
PN
PN
line card
125 s) the terminal may already have started sending a second HDLC-frame. On
adapter -
phone
phone
line card -
line card -
line card -
t
phone
adapter -
phone
DCDU
, the full selection counter value must be set so that the D-channel arbiter re-
Circuit Chain
ELIC + OCTAT-P
+ ISAC-P TE
ELIC + OCTAT-P
+ ISAC-P TE +
SBCX + ISAC-S
ELIC + OCTAT-P
+ ISAC-P TE +
ISAC-P TE +
ISAC-P TE
ELIC + QUAT-S
+ ISAC-S TE
Number of Frames (= 125 s)
Blocked
min.
87
4
9
9
4
Available
max.
13
13
8
8
Functional Description
Available
min.
4
5
9
4
t
CCDD
PEB 20550
PEF 20550
(e.g. after
Blocked
max.
13
8
9
8
01.96