DS33X161+ Maxim Integrated Products, DS33X161+ Datasheet - Page 72

• Manufacturer Part Number: DS33X161+
• Description: IC MAPPING ETHERNET 256CSBGA
• Manufacturer: Maxim Integrated Products

Specifications of DS33X161+

• Applications: Data Transport
• Interface: Parallel/Serial
• Voltage - Supply: 1.8V, 2.5V, 3.3V
• Package / Case: 256-CSBGA
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.16.6 Programming the Priority Table
The user-programmable Priority Table is accessed indirectly through the SU.PTC, SU.PTAA, SU.PTWD,
SU.PTRD, and SU.PTSA registers. The device contains a single table, with the MSB of the table address
(SU.PTAA.PTAA) used to distinguish the LAN port in multi-port devices. When a frame is received, the PCP or
DSCP value in the received frame is the address used to look up the user-programmed priority level in the Priority
Table.
The device does not require that the priority mapping be linear or monotonic. Arbitrary assignments are allowed.
Note that while the DSCP/PCP protocol definitions use a higher value to indicate a higher priority, the device uses
a lower value to indicate a higher priority. As an example, for the values PCP = 000b and DSCP = 00000b (as
defined by their protocol definitions as lowest priority) most users will choose to assign the associated priority table
address location (SU.PTAA.PTAA[6:1]=000000b) a value of 11b, indicating the lowest possible priority. Similarly
for the values PCP = 111b and DSCP = 111111b, typically the associated Priority Table address will be assigned a
value of 00b. Example Priority Table configurations for a single port are shown in the tables below.
Table 8-12. Example Priority Table Configuration for DSCP
* More guidance on priority mapping for legacy compatibility can be found in RFC 2474.
Rev: 063008
PTAA[6:1]
________________________________________________ DS33X162/X161/X82/X81/X42/X41/X11/W41/W11
000000
000001
000010
000011
000100
000101
000110
000111
001000
001001
001010
001011
001100
001101
001110
001111
SU.PTWD/
SU.PTRD
11
11
11
10
10
10
10
10
10
10
10
10
10
10
10
10
PTAA[6:1]
010000
010001
010010
010011
010100
010101
010110
010111
011000
011001
011010
011011
011100
011101
011110
011111
SU.PTWD/
SU.PTRD
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
PTAA[6:1]
100000
100001
100010
100011
100100
100101
100110
100111
101000
101001
101010
101011
101100
101101
101110
101111
SU.PTWD/
SU.PTRD
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
PTAA[6:1]
110000
110001
110010
110011
110100
110101
110110
110111
111000
111001
111010
111011
111100
111101
111110
111111
SU.PTWD/
SU.PTRD
72 of 375
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
00