w6692 Winbond Electronics Corp America, w6692 Datasheet - Page 30

• Manufacturer Part Number: w6692
• Description: Pci Bus Isdn S/t-controller
• Manufacturer: Winbond Electronics Corp America

7.2.4 D Channel Access Control
The priority management procedure as specified in ITU-T I.430 is fully implemented in W6692.
transmission is immediately stopped and the echo channel is monitored to attempt the next D channel access. The layer 1 module
uses an internal signal to inform layer 2 module of the collision condition (DRDY bit goes inactive in D_XSTA register).
TABLE 7.4 D PRIORITY CLASSES
for setting the priority classes:
TABLE 7.5 D PRIORITY COMMANDS/INDICATIONS
Command
Activate request, set priority 8
Activate request, set priority 10
Indication
Activate indication with priority 8
Activate indication with priority 10 AI10
7.2.5 Frame Alignment
Priority class
1
Priority class
2
The D channel access control includes collision detection and priority management. The collision detection is always enabled.
A collision is detected if the transmitted D bit and the received echo bit do not match. When this occurs, D channel
There are two priority classes: class 1 and class 2. Within each class, there are normal and lower priority levels.
The selection of priority class is via the AR8/AR10 command. The following table summarizes the commands/indications used
Normal level
10
8
Symbol Code
AR8
AR10
Abbr.
AI8
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
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W6692 PCI ISDN S/T-Controller
Publication Release Date:
Preliminary Data Sheet
Sep 30, 1999
Revision 0.9