Motorola MPC8260 - Manual (Page 828)

29-48 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part IV. Communications Processor Module
Table 29-18 describes AAL5-ABR protocol-speciÞc RCT Þelds.
29.10.2.2.3 AAL1 Protocol-SpeciÞc RCT
Figure 29-28 shows the AAL1 protocol-speciÞc area of an RCT entry.
Table 29-19 describes AAL1 protocol-speciÞc RCT Þelds.
Table 29-18. ABR Protocol-Specific RCT Field Descriptions
Offset Bits Name Description
0x0E С С AAL5 protocol-speciÞc
0x16 Ñ PCR Peak cell rate. The peak number of cells per second of the current ABR channel. The ACR
(allowed cell rate) never exceeds this value. PCR uses the ATMF TM 4.0 ßoating-point format.
0x18 0Ð3 RDF Rate decrease factor for the current ABR channel. Controls the decrease in cell transmission
rate upon receipt of a backward RM cell. RDF represents a negative exponent of two, that is, the
decrease factor = 2
-RDF . The decrease factor ranges from 1/32768 (RDF=0xF) to 1 (RDF=0).
4Ð7 RIF Rate increase factor of the current ABR channel. Controls the increase in the cell transmission
rate upon receipt of a backward RM cell. RIF represents a negative exponent of two, that is, the
increase factor = 2
-RIF . The increase factor ranges from 1/32768 (RIF=0xF) to 1 (RIF=0).
8Р15 С AAL5 protocol-speciÞc
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Offset + 0x0E Ñ PFM SRT INVE STF Ñ
Offset + 0x10 SRTS_TMP С С SRTS Device
Offset + 0x12 Ñ Valid Octet Size (VOS) SPV Structured Pointer (SP)
Offset + 0x14 RBDCNT
Offset + 0x16 Ñ SN
Offset + 0x18 Ñ SNEM Ñ RXBM Ñ
Figure 29-28. AAL1 Protocol-Specific RCT