Datasheet

 2017 Microchip Technology Inc. DS00002348A-page 57
KSZ8873MLL/FLL/RLL
4.5 Advanced Control Registers (Registers 96-198)
The IPv4/IPv6 TOS Priority Control Registers implement a fully decoded, 128-bit Differentiated Services Code Point
(DSCP) register set that is used to determine priority from the Type of Service (TOS) field in the IP header. The most
significant 6 bits of the TOS field are fully decoded into 64 possibilities, and the singular code that results is compared
against the corresponding bits in the DSCP register to determine the priority.
TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198)
Bit Name R/W Description Default
Register 96 (0x60): TOS Priority Control Register 0
7-6 DSCP[7:6] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x03.
00
5-4 DSCP[5:4] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x02.
00
3-2 DSCP[3:2] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x01.
00
1-0 DSCP[1:0] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x00.
00
Register 97 (0x61): TOS Priority Control Register 1
7-6 DSCP[15:14] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x07.
00
5-4 DSCP[13:12] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x06.
00
3-2 DSCP[11:10] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x05.
00
1-0 DSCP[9:8] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x04.
00
Register 98 (0x62): TOS Priority Control Register 2
7-6 DSCP[23:22] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x0B.
00
5-4 DSCP[21:20] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x0A.
00
3-2 DSCP[19:18] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x09.
00
1-0 DSCP[17:16] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x08.
00
Register 99 (0x63): TOS Priority Control Register 3
7-6 DSCP[31:30] R/W
The value in this field is used as the frame’s priority
when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic
Class value is 0x0F.
00