AX88140AP ETC, AX88140AP Datasheet - Page 28

• Manufacturer Part Number: AX88140AP
• Description: Fast Ethernet MAC Controller
• Manufacturer: ETC

Filtering Buffer
with multicast addresses by 64 bits array. For any incoming frame with a multicast destination
address, the AX88140A applies the standard Ethernet cyclic redundancy check function to the
destination address, then uses the most significant 6 bits of the result as a bit index into the table. If
the indexed bit is set, the frame is accepted. If the bit is reset, the frame is rejected.
Description of Filtering Buffer
Layout of Filtering Buffer
4.2.12 General -Purpose Port Register (REG12)
4.2.13 Filtering Index (REG13)
4.2.14 Filtering data (REG14)
FIELD
FIELD
The AX88140A stores one Ethernet address for local physical address and filters the packets
31:6
31:0
Field
5:0
NUMBER
31:9
NUMBER
BUFFER
7:0
BUFFER
8
AX88140A
0
0
1
2
3
R/W/C
R/W/C
R/W
R/W
-
R/W/C
Tab - 26 REG11 General -Purpose Timer Register Description
R/W
R/W
Tab - 27 REG12 General -Purpose Port Register Description
-
BYTE 0 - 3 OF LOCAL PHYSICAL ADDRESS
BYTE 4 - 5 OF LOCAL PHYSICAL ADDRESS IN THE LEAST SIGNIFICANT WORD
BIT 0 - 31 OF MULTICAST ADDRESS FILTERING TABLE
Bit 32 - 63 of multicast address filtering table
ADDRESS BYTE 3
Reserved.--Written as “0” for future compatibility concern.
FI - Filtering Index
When writing data to filtering buffer, uses filtering index register REG13 to point the position (buffer
number) in filtering buffer. The valid value is between 0 and 3.
FD - Filtering Data
By indexed by filtering index register REG13, write the filtering data register REG14 to put filtering
address/hash table into filtering buffer..
Tab - 28 REG13 Filtering Index Register Description
Tab - 29 REG14 Filtering Data Register Description
PHYSICAL
BYTE 3
Reserved.--Written as “0” for future compatibility concern.
GPC - General Purpose Control .
When a hardware reset is initiated, all gep pins
become input pins.
MD - General Purpose Mode and Data
Tab - 30 Description of Filtering Buffer
PHYSICAL ADDRESS
BYTE 2
BYTE 2
DESCRIPTION
DESCRIPTION
DESCRIPTION
28
Description
PHYSICAL ADDRESS
BYTE 1
BYTE 1
1
0
ASIX ELECTRONICS CORPORATION
Indicate next write REG12<7:0> is use
for define General purpose port in/out
direction.
Indicate next write REG12<7:0> is use
for read/write general purpose port data.
PHYSICAL ADDRESS
PRELIMINARY
BYTE 0
BYTE 0