RS8234EBGC Mindspeed Technologies, RS8234EBGC Datasheet - Page 140

• Manufacturer Part Number: RS8234EBGC
• Description: RS8234EBGC ATM XBR SAR
• Manufacturer: Mindspeed Technologies

5.0 Reassembly Coprocessor
5.7 Reassembly Control and Status Structures
5.7.1 Channel Lookup Structures
Figure 5-16. VPI/VCI Channel Lookup Structure
5-36
Table 5-3. Normal VPI Index Table Entry Format
Word
0
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Base Register (16)
RSM_TBASE
(RSM_ITB)
VCI_RANGE
VPI [11:0]
performs EPD on channels marked for packet discard due to the status overflow
condition when a cell is received on any of those channels. Cells up to and
including the next EOM will also be discarded. Status queue overflow protection
can be globally disabled by setting RSM_CTRL0(RSM_STAT_DIS) to a logic
high.
NOTE:
5.7 Reassembly Control and Status Structures
The reassembly coprocessor uses a VPI/VCI Table Index mechanism employing
direct index lookup in order to assign each arriving cell to a virtual channel, based
on its VPI/VCI value.
without EN_PROG_BLK_SZ (RSM_CTRL1) enabled.
programmable VCC Table and VCI Index Table block size enabled.
After a status group has exited a full condition, the RSM coprocessor
Table 5-3
Table 5-4
Table 5-5
(Either 256 or 4096 entries)
Avoid having the Status Queue Overflow (or Full Condition) and DMA
FIFO Buffer Full conditions at the same time.
Mindspeed Technologies
VPI Index Table
describes the normal VPI Index Table format (one word per entry)
describes the VPI Index Table format (two words per entry) with
describes the field definitions for the VPI Index Table fields.
VCI_IT_PNTR
Figure 5-16
VCI [15:x]
Where x=6; or value of VCI_IT_BLK_SZ
ATM ServiceSAR Plus with xBR Traffic Management
with EN_PROG_BLK_SZ enabled
illustrates this lookup mechanism.
™
VCI_IT_PNTR
VCC_BLOCK_INDEX
VCI Index Table
(For One VPI)
28234-DSH-001-B
RS8234
100074_037