T8207 Datasheet, PDF (29/158 Pages) Agere Systems – ATM Interconnect

Advance Data Sheet
September 2001
CelXpres T8207
ATM Interconnect
8 Look-Up Table (continued)
0000h
0200h
0400h
0600h
0800h
0A00h
0C00h
0E00h
1000h
1200h
1400h
1600h
1800h
1A00h
1C00h
1E00h
2000h
7FFFFh
ROUTING LOOK-UP MEMORY MAP
OAM CELL ROUTING PORT 0
OAM Cell Routing Port 1
OAM CELL ROUTING PORT 2
OAM CELL ROUTING PORT 3
OAM CELL ROUTING PORT 4
OAM CELL ROUTING PORT 5
OAM CELL ROUTING PORT 6
OAM CELL ROUTING PORT 7
OAM CELL ROUTING PORT 8
OAM CELL ROUTING PORT 9
OAM CELL ROUTING PORT 10
OAM CELL ROUTING PORT 11
OAM CELL ROUTING PORT 12
OAM CELL ROUTING PORT 13
OAM CELL ROUTING PORT 14
OAM CELL ROUTING PORT 15
ANY PURPOSE LOOK-UP MEMORY
SHARED BETWEEN EACH OF THE
16 PORTS
+0000h
+00F8h
+0100h
+0108h
+0110h
+0118h
+0120h
+0128h
+0130h
+01F8h
OAM CELL ROUTING PORT X RECORD MAP
VP OAM VCI = 0 (F4)
•
•
•
VP OAM VCI = 31 (F4)
VP OAM VCI = 6 & PT = “110” (F4) (RM-VPC)
VC OAM PTI = “100” (F5)
VC OAM PTI = “101” (F5)
VC OAM PTI = “110” (F5)
VC OAM PTI = “111” (F5)
RESERVED
RESERVED
•
•
•
RESERVED
Figure 4. Translation RAM Memory Map—8-Byte Records, for Up to 16 Ports
The four translation record types (VCI, OAM/RM, VPI only, and VPI for VPI/VCI) for 8-byte records are illustrated in
Figure 6. There are two types of VPI translation records: one for VPI translation only and one for VPI/VCI transla-
tion. The VPI only translation record differs from other records in that it has the SH and SL bits which are used to
indicate full or partial VPI translation. (See Table 12, the VPI Value Truth Table.) The other VPI record is used when
VPI/VCI translation occurs. It has the VCI offset bits and max VCI value bits which are used to point to the VCI
record where translation and routing information reside. The maximum VCI offset is 19 bits in length; therefore,
only bits 3 through 18 are stored in the VPI record.
To address the appropriate VCI translation record, the VCI from the cell’s header is multiplied by 8 and added to
bits 3 through 18 of the VCI offset which is obtained from the VPI record. This sum is the final offset into the look-
up table. This final offset should then be added to the translation RAM memory beginning address 100000h (Table
125) to obtain the final address. The max VCI value indicates the maximum number of VCI translation records in
the table. Therefore, if the VCI from the cell’s header is greater than the max VCI value, the cell’s VCI is out of
range and is counted as a misrouted cell. Note that VPI records from different ports may reference the same VCI
translation record. Other control bits in these records are described following Figure 6.
Agere Systems Inc.
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