W6691CD WINBOND [Winbond], W6691CD Datasheet - Page 35

• Manufacturer Part Number: W6691CD
• Description: ISDN S/T Interface Transceiver
• Manufacturer: WINBOND [Winbond]

7.2.5 D Channel Access Control
is always enabled. The priority management procedure as specified in ITU-T I.430 is fully implemented in
W6691.
channel transmission is immediately stopped, and the echo channel is monitored to attempt the next D
channel access.
levels.
TABLE 7.8 D PRIORITY CLASSES
The selection of priority class is via the AR8/AR10 command. The following table summarizes the
commands/indications used for setting the priority classes:
TABLE 7.9 D PRIORITY COMMANDS/INDICATIONS
Command
Activate request, set priority 8
Activate request, set priority 10
Indication
Activate indication with priority 8 AI8
Activate indication with priority 10 AI10
Priority class 1
Priority class 2
The D channel access control includes collision detection and priority management. The collision detection
A collision is detected if the transmitted D bit and the received echo bit do not match. When this occurs, D
There are two priority classes: class 1 and class 2. Within each class, there are normal and lower priority
Normal level
10
8
Symbol Code
AR8
AR10
Abbr.
Lower level
11
9
1000
1001
1100
1101
Remarks
Activation command, set D channel priority to 8
Activation command, set D channel priority to 10
Remarks
Info 4 received, D channel priority is 8 or 9
Info 4 received, D channel priority is 10 or 11
35
Preliminary W6691
Publication Release Date: Sep 2001
Revision 1.1