Datasheet
KSZ8873MLL/FLL/RLL
DS00002348A-page 70 2017 Microchip Technology Inc.
and FID+SA lookups are performed. The FID+DA look up determines the forwarding ports. If FID+DA fails, the packet
will be broadcast to all the members (excluding the ingress port) of the VLAN. If FID+SA fails, the FID+SA will be
learned.
Examples:
1. VLAN Table Read (read the 3rd entry)
Write to reg. 121 (0x79) with 0x14 // Read VLAN table selected
Write to reg. 122 (0x7A) with 0x02 // Trigger the read operation
Then,
Read reg. 129 (0x81), VLAN table bits [19:16]
Read reg. 130 (0x82), VLAN table bits [15:8]
Read reg. 131 (0x83), VLAN table bits [7:0]
2. VLAN Table Write (write the 7th entry)
Write to reg. 129 (0x81), VLAN table bits [19:16]
Write to reg. 130 (0x82), VLAN table bits [15:8]
Write to reg. 131 (0x83), VLAN table bits [7:0]
Write to reg. 121 (0x79) with 0x04 // Write VLAN table selected
Write to reg. 122 (0x7A) with 0x06 // Trigger the write operation
4.8 Dynamic MAC Address Table
The KSZ8873 maintains the dynamic MAC address table. Only read access is allowed.
Example:
Dynamic MAC Address Table Read (read the 1st entry and retrieve the MAC table size)
Write to reg. 121 (0x79) with 0x18 // Read dynamic table selected
Write to reg. 122 (0x7A) with 0x00 // Trigger the read operation
Then,
Read reg. 123 (0x7B), bit [7] // if bit 7 = 1, restart (reread) from this register dynamic table bits [66:64]
TABLE 4-12: FORMAT OF DYNAMIC MAC ADDRESS TABLE (1K ENTRIES)
Bit Name R/W Description Default
71 Data Not Ready RO
1 = entry is not ready, continue retrying until this bit is
set to 0
0 = entry is ready
—
70-67 Reserved RO Reserved —
66 MAC Empty RO
1 = there is no valid entry in the table
0 = there are valid entries in the table
1
65-56
Number of Valid
Entries
RO
Indicates how many valid entries in the table
0x3ff means 1k entries
0x001 means 2 entries
0x000 and bit 66 = 0 means 1 entry
0x000 and bit 66 = 1 means 0 entry
00_0000_0000
55-54 Time Stamp RO 2 bits counter for internal aging —
53-52 Source Port RO
The source port where FID+MAC is learned
00 = port 1
01 = port 2
10 = port 3
00
51-48 FID RO Filter ID 0x0
47-0 MAC Address RO 48-bit MAC Address
0x0000_0000
_0000