78Q8430 Datasheet, PDF (39/88 Pages) Teridian Semiconductor Corporation – 10/100 Ethernet MAC and PHY

DS_8430_001
78Q8430 Data Sheet
Hex
Value
0x14
0x15
0x16
0x17
0x18
0x1A
0x1B
0x1C
0x1D
0x1E
0x1F
Binary
Value
10100b
10101b
10110b
10111b
11000b
11010b
11011b
11100b
11101b
11110b
11111b
Name
Action Taken
THXA
SETMC
VLAN
SETBC
TOC
DEC
MCTL
TDPH
TDLTH
TDPL
TDLTL
The high-order nibble of the classification result is assigned the value of
the high-order nibble value of ‘X’.
Mark the frame as multicast for Rx statistics purposes.
Mark the frame as VLAN tagged for length checking and statistics.
Mark the frame as broadcast for Rx statistics purposes.
The control logic counter value is initialized to the value contained in the
Byte Offset field. No offset is applied.
The control logic counter value is decremented. If the counter has
reached zero then the control logic will decrement the previous hit value
used to generate the next CAM reference word by one.
Classify the frame as a MAC control frame. This also sets the Len/Type
LSB.
The pause counter most significant byte is set from the frame data.
The Len/Type most significant byte is set from the frame data.
The pause counter least significant byte is set from the frame data.
The Len/Type least significant byte is set from the frame data.
RCR Match Control
The value of the Match Control field will determine how the control logic generates the next CAM
reference word.
Value
00b
10b
01b
11b
Name
DONE
MD
MX
DROP
Table 27: RCR Match Control
Action Taken
No more CAM reference words are generated. No further classification is
done for the current frame.
The next frame data is used to generate the next CAM reference word.
The ‘X’ value is used in place of the frame data to generate the next CAM
reference word.
Drop the frame. If this is executed within the first 128 bytes of the frame
then the entire frame is dropped from the QUE. No more CAM reference
words are generated.
6.7.3 Frame Format
The following table shows the format of an Ethernet frame. The fields are in the order that the
classification engine sees them, from left to right. The byte count for each field is specified on the bottom
row of the table.
Destination
Address
6 Bytes
Table 28: Ethernet Frame for Classification
Source
Address
6 Bytes
Len/Typ
Hi Lo
1B 1B
LLC Data
User
Pad
0-1500B 46-0B
MSB
CRC (FCS)
4 Bytes
LSB
If the Len/Type field contains a 16-bit value that is less than 0x0600, the field is interpreted as a length
field that specifies the number of bytes in the User field. If the value is greater than or equal to 0x0600,
the type interpretation is to be used.
6.7.4
Default CAM Rule Summary
This section provides the default rules that the 78Q8430B CAM is loaded with on reset.
Rev. 1.2
39