PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 81

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

Figure 30
Monitor Channel Transmitter and MTO Enabled
The transmitter is reset in 6 ms intervals in the frames shown above. In case the
transmission of a monitor message has not been completed before the transmitter is
reset, the complete message will be lost. A message that has been lost due to the
interruption of a monitor reset will not be retransmitted.
To prevent this loss of monitor messages, the IEC-Q will only commence a monitor
transmission if more than 16 IOM
next reset occurs. Transmission thus does not start during frame numbers 33 … 48 and
81 … 96. To ensure correct transmission the receiver must not delay the receive
procedure for more than the following value:
• 2-byte transmission: max. speed = 8 frames => max. controller (receive) delay =
Monitor Channel Receiver and MTO Enabled
The receiver is reset in 6 ms intervals in the frames shown above. In case the reception
of a monitor message has not been completed before the receiver is reset, the complete
message can be lost because the generation of an abort request can not be guaranteed.
To prevent this loss of monitor messages the PEB 2091 will only commence a monitor
reception (i.e. acknowledge the 1st received byte) if more than 16 IOM
available for reception before the next reset occurs. Reception thus does not start during
frame numbers 33 … 48 and 81 … 96. To ensure correct reception, the transmitter must
not delay the receive procedure for more than the following value:
• 2-byte reception: max. speed = 7 frames => max. controller (transmit) delay = 9
Semiconductor Group
8 frames.
frames.
IOM
Receive
U Frame
Superframe
Marker
Possible Start of
Monitor Procedure
R
Frame
Monitor Access with MTO Enabled
1
1 isw
12
Reset
2
24
®
3
-2 frames will be available for transmission before the
32
36
Transfer
4
Start of
New
No
81
Superframe
48
49
5
60
Reset
6
72
7
Functional Description
80
84
Transfer
8
Start of
New
®
No
-2 frames will be
Data Sheet 01.99
96
1
PEB 2091
PEF 2091
ITD04232