MOTOROLA
Chapter 24. SCC Ethernet Mode
24-9
Part IV. Communications Processor Module
0x54
MAX_B
Hword Maximum BD byte count.
0x58
GADDR1
Hword Group address Þlter 1Ð4. Used in the hash table function of the group addressing
mode. Write zeros to these values after reset and before the Ethernet channel is
enabled to disable all group hash address recognition functions. The
SET
GROUP
ADDRESS
command is used to enable the hash table.
0x5A
GADDR2
0x5C
GADDR3
0x5E
GADDR4
0x60
TBUF0_DATA0 Word
Save area 0Ñcurrent frame.
0x64
TBUF0_DATA1 Word
Save area 1Ñcurrent frame.
0x68
TBUF0_RBA0
Word
0x6C
TBUF0_CRC
Word
0x70
TBUF0_BCNT Hword
0x72
PADDR1_H
Hword The 48-bit individual address of this station into this location. PADDR1_L is the
lowest order hword and PADDR1_H is the highest order hword.
0x74
PADDR1_M
0x76
PADDR1_L
0x78
P_PER
Hword Persistence. Lets the Ethernet controller be less aggressive after a collision.
Normally, 0x0000. It can be a value between 1 and 9 (1 is most aggressive). The
value is added to the retry count in the backoff algorithm to reduce the chance of
transmission on the next time slot.
Note: Using P_PER is fully allowed in the Ethernet/802.3 specifications. A less
aggressive backoff algorithm used by multiple stations on a congested Ethernet
LAN increases overall throughput by reducing the chance of collision. PSMR[SBT]
offers another way to reduce the aggressiveness of the Ethernet controller.
0x7A
RFBD_PTR
Hword Rx Þrst BD pointer.
0x7C
TFBD_PTR
Hword Tx Þrst BD pointer.
0x7E
TLBD_PTR
Hword Tx last BD pointer.
0x80
TBUF1_DATA0 Word
Save area 0Ñnext frame.
0x84
TBUF1_DATA1 Word
Save area 1Ñnext frame.
0x88
TBUF1_RBA0
Word
0x8C
TBUF1_CRC
Word
0x90
TBUF1_BCNT Hword
0x92
TX_LEN
Hword Tx frame length counter.
0x94
IADDR1
Hword Individual address Þlter 1Ð4. Used in the hash table function of the individual
addressing mode. Zeros can be written to these values after reset and before the
Ethernet channel is enabled to disable all individual hash address recognition
functions. The
SET
GROUP
ADDRESS
command is used to enable the hash table.
0x96
IADDR2
0x98
IADDR3
0x9A
IADDR4
0x9C
BOFF_CNT
Hword Backoff counter.
Table 24-1. SCC Ethernet Parameter RAM Memory Map (Continued)
Offset
1
Name
Width
Description
Summary of Contents for MPC8260 PowerQUICC II
Page 1: ...MPC8260UM D 4 1999 Rev 0 MPC8260 PowerQUICC II UserÕs Manual ª ª ...
Page 66: ...lxvi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA ...
Page 88: ...1 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 120: ...2 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 138: ...Part II iv MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II Configuration and Reset ...
Page 184: ...4 46 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II ConÞguration and Reset ...
Page 202: ...Part III vi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 266: ...8 34 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 382: ...10 106 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 392: ...11 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 430: ...Part IV viii MOTOROLA Part IV Communications Processor Module ...
Page 490: ...14 36 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 524: ...17 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
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Page 980: ...A 4 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Appendixes ...
Page 1002: ...Index 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA INDEX ...
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