DS_8430_001
78Q8430 Data Sheet
For an arbitrary unicast filter number N, the following procedure should be used to set the address and
mask values:
STEP 1. Write address and mask byte [0] to the CAM. CAM rule 0x70+N should be written as shown in
the following table:
Reg.
Field
Value to write
CAR
ADDR
0x70+N
RMR Data Match
Data Mask
Value of MAC address byte [0]
Value of mask byte [0] from the Wild Card setting (0xFF is
for a perfect match)
Previous Hit Match
Previous Hit Mask
RCR Byte Offset
0x00 to disable the filter
0x00
Retain default: 0x00
Retain default: 0
Retain default: NOP
Retain default: MD
Interrupt
Control Logic Action
Match Control
STEP 2. Write address and mask byte [1] through byte [4] to the CAM. For each byte the CAM rule
indicated by Table 24 based on the filter number, N, and byte number should be written as
follows.
Reg.
Field
Value to write
CAR
ADDR
byte [1]:
byte [2]:
0x58+N
byte [3]:
byte [4]:
0x68+N
0x50+N
0x40+N
RMR Data Match
Data Mask
Value of MAC address byte [1] … byte [4]
Value of mask byte [1] . . . byte [4]
Previous Hit Match
Previous Hit Mask
RCR Byte Offset
Value of the CAM rule used by the previous byte
0x7F
Retain default: 0x00
Retain default: 0
Interrupt
Control Logic Action
Match Control
Retain default: NOP
Retain default: MD
Unlike the settings for byte [0], the Previous Hit Mask field is set to 0x7F and the Previous Hit
Match field is always set to the value of the CAM rule used by the previous byte. As an
example, the Previous Hit Mask fields for filter #1 would be 0x71, 0x69, 0x59 and 0x51, for byte
[1] through byte [4] respectively.
STEP 3. Write address and mask byte [5] to the CAM. CAM rule 0x30+N should be written as follows.
Reg.
Field
Value to write
CAR
ADDR
0x30+N
RMR Data Match
Data Mask
Value of MAC address byte [5]
Value of mask byte [5]
Set to the CAM rule that was used for byte [4] (0x40+N).
0x7F
Previous Hit Match
Previous Hit Mask
RCR Byte Offset
Retain default: 0x00
Interrupt
Retain default: 0
Control Logic Action
Match Control
Set to TAX
Retain default: MD
Rev. 1.2
35
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
