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CHAPTER 4 ATM CELL PROCESSOR
Preliminary User’s Manual S14767EJ1V0UM00
317
(2) Packet descriptor
Figure 4-34. Transmit Queue Packet Descriptor
31
0
1
31
0
BUFFER DIRECTORY ADDRESS
CLPM
GFC
CPCS-UU
30
28 27
24 23
16 15
ENC
29
PTI
26
20
IM
C
10
18
AAL
MB
17
19
CPI
8
7
Encapsulation mode is indicated.
11
PPP-NT encapsulation
10
PPP encapsulation
01
LLC encapsulation
00
No encapsulation
CLP bit in the packet header is indicated.
00
Sets CLP bit in all cells as 0.
11
Sets CLP bit in all cells as 1.
01
Sets CLP bit in all cells except last cell as 1, and only CLP bit in last cell as 0.
10
Not used.
PTI field in the packet header is indicated. Since this field indicates cell payload type, takes different
transmission procedure according to this field .
000
User data cell without congestion.
001
User data cell without congestion. Last cell in the packet.
Prohibited to be set by user. If this value is set, treats as 000.
010
User data cell with congestion.
011
User data cell with congestion. Last cell in the packet.
Prohibited to be set by user. If this value is set, treats as 010.
100
OAM F5 cell used to carry information between segments
101
OAM F5 cell used to carry information between end to end.
110
RM cell used in ABR service. Prohibited to be set by user.
111
Prohibited to be set by user.
GFC field in the packet header is indicated.
Indicates if ATM Cell Processor sends the transmitting indication to V
R
4120A RISC Processor.
1 : Doesn’t send transmitting indication to V
R
4120A RISC Processor.
0 : Sends transmitting indication to V
R
4120A RISC Processor.
Indicates if CRC-10 should be inserted or not.
1 : Insert CRC-10 in every cell.
0 : Not insert CRC-10.
Indicates if the transmitting packet is AAL-5 packet or not.
1 : AAL-5 packet.
0 : Not AAL-5 packet. ATM Cell Processor treats cells in this packet as Raw cell.
Mailbox number for storing transmitting indication for this packet is indicated.
1 : Mailbox number 3.
0 : Mailbox number 2.
User information. In AAL-5 mode, ATM Cell Processor inserts the pattern in this field to the CPI field
in the trailer. In Raw cell mode, this field is ignored.
User information. In AAL-5 mode, ATM Cell Processor inserts the pattern in this field to the CPI field
in the trailer. In Raw cell mode, this field is ignored.
ENC
CLPM
PTI
GFC
IM
C10
AAL
MB
CPCS-UU
CPI