Motorola PowerQUICC II MPC8280 Series Reference Manual page 1034

VCI/VPI Address Lookup Mechanism
Figure 31-8 shows the VC pointer address compression from Table 31-6.
VCI
VC_MASK
VC Pointer
Figure 31-8. VC Pointer Address Compression
31.4.3 Misinserted Cells
If the address lookup mechanism cannot find a match (MS=1), the cell is discarded and
ATM layer statistics are updated, as described in Section 31.8, "ATM Layer Statistics."
31.4.4 Receive Raw Cell Queue
Channel one in the RCT is reserved as a raw cell queue. The user should program channel
one to operate in AAL0 protocol. The receive raw cell queue is used for removing
management cells from the regular cell flow to the host. When a management cell is sent
to the receive raw cell queue, the CP sets RxBD[OAM]. The ALL0 BD specifies the
channel code associated with the current OAM cell.
The following are optionally removed from the regular flow and sent to the raw cell queue:
• Segment F5 OAM (PTI = 0b100). To enable F5 segment filtering, set RCT[SEGF].
• End-to-end F5 OAM (PTI = 0b101). To enable F5 end-to-end filtering, set
RCT[ENDF].
• RM cells (PTI = 0b110). When ABR flow is enabled the cells are terminated
internally; otherwise, they are sent to the raw cell queue.
• Reserved PTI value (PTI = 0b111). Always sent to the raw cell queue.
• VCI value: 3, 4, 6, 7–15. To enable VCI filtering set the associated bit in the VCIF
entry in the parameter RAM.
31-20
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