Datasheet
2017 Microchip Technology Inc. DS00002348A-page 47
KSZ8873MLL/FLL/RLL
Register 11 (0x0B): Global Control 9
7-6
CPU Interface Clock
Selection
R/W
00 = 31.25 MHz supports SPI speed below 6 MHz
01 = 62.5 MHz supports SPI speed between 6 MHz to
12.5 MHz
10 = 125 MHz supports SPI speed above 12.5 MHz
Note: Lower clock speed will save more power; It is
better set to 31.25 MHz if SPI doesn’t request a high
speed.
10
5-4 Reserved RO N/A Don’t Change 00
3-2 Reserved RO N/A Don’t Change 10
1 Reserved RO N/A Don’t Change 0
0 Reserved RO N/A Don’t Change 0
Register 12 (0x0C): Global Control 10
7-6 Tag_0x3 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x3.
01
5-4 Tag_0x2 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x2.
01
3-2 Tag_0x1 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x1.
00
1-0 Tag_0x0 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x0.
00
Register 13 (0x0D): Global Control 11
7-6 Tag_0x7 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x7.
11
5-4 Tag_0x6 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x6.
11
3-2 Tag_0x5 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x5.
10
1-0 Tag_0x4 R/W
IEEE 802.1p mapping. The value in this field is used
as the frame’s priority when its IEEE 802.1p tag has a
value of 0x4.
10
Register 14 (0x0E): Global Control 12
7
Unknown Packet
Default Port Enable
R/W
Send packets with unknown destination MAC
addresses to specified port(s) in bits [2:0] of this regis-
ter.
0 = disable
1 = enable
0
6
Drive Strength of I/O
Pad
R/W
1: 16 mA
0: 8 mA
1
5 Reserved RO
Reserved
Do not change the default values.
0
4 Reserved RO
Reserved
Do not change the default values.
0
TABLE 4-6: GLOBAL REGISTERS (0-15) (CONTINUED)
Bit Name R/W Description Default