Technical information

7-78
AIC-6915 Ethernet LAN Controller Programmer’s Manual
MskRandomNum Register
Type: R/W
Internal Registers Subgroup: MAC Registers
Byte Address: 5028h - 502Bh
TotalTxCnt Register
Type: R/W
Internal Registers Subgroup: MAC Registers
Byte Address: 5034h- 5037h
Table 7-101. MskRandomNum Register
Bit(s) rw
Reset
Value Description/Function
31:10 r/w 0
Reserved:
Always read as 0.
9:0 r/w 0
MskRandomNum:
This is the sliding window mask result on
R
ANDOM
N
UM
G
EN
register. This mask is used to implement the
truncated binary exponential backoff algorithm. For example, only
the LSB of RandomNumGen is evaluated to determine the number
of slot times of delay before the first retransmission. It may be either
0 or 1. Only the 2 least-significant-bits of
R
ANDOM
N
UM
G
EN
are
evaluated before the second retransmission. It may be 0, 1, 2, or 3
slot times, etc. This field should only be written for test purposes,
such as for loading a predictable number rather than a random
number.
Table 7-102. TotalTxCnt Register
Bit(s) rw
Reset
Value Description/Function
31:16 r/w 0
Reserved:
Always read as 0.
15:0 r/w 0
TotalTxByteCnt:
This field is used for counting the total number of
bytes transmitted on the wire for the current packet, including all
bytes from collided attempts. It should only be written for test
purposes.