
TC9208M
Preliminary Data Sheet
configuration (default is IP). If no header is found or corresponding prioritizations are disabled then port
based prioritization is executed. When EEPROM is present an additional method of prioritization is
available. This method consists of selecting the highest service class from all classes corresponding to
the enabled prioritization sources (IP, VLAN and port based). For both methods, when no prioritization
source is available the default CoS is used (default is normal priority – CoS1 but it can be also changed
by EEPROM configuration).
The CoS feature can be configured by adjusting shared configuration pins and/or programming
EEPROM Register settings. VLAN prioritization can be enabled by EnVLPr shared configuration pin or
by EEPROM register settings, while EnIPPr shared configuration pin or the EEPROM Register settings
can enable IP prioritization. The shared configuration pins are sampled during reset.
The per port basis CoS can be set using PriClass[x][1:0] shared configuration pins or configuring
EEPROM registers, where x stands for port number. The port based prioritization can be disabled from
EEPROM settings only.
Configuration
Pins Latched
Description
PriClass[x][1:0] TxDataX_[1:0] Set the priority class per port basis
'00' – the port has class 0 priority(lowest priority)
'01' – the port has class 1 priority
'10' – the port has class 2 priority
'11' – the port has class 3 priority(highest priority)
EnIPPr
TxData3_7
Enable/disable IP prioritization
‘0’ – IP priority within the received packet (if exists) is ignored
‘1’ – IP priority within the received packet (if exists) is considered
EnVLPr
TxData3_4
Enable/disable VLAN prioritization
‘0’ – VLAN priority within the received packet (if exists) is ignored
‘1’ – VLAN priority within the received packet (if exists) is considered
Selects one of four mappings for the 8 level precedence extracted
from frame’s IP header to the 4 CoS offered by TC9208M
(C0, C1, C2, C3 – class 0, 1, 2, 3 of service)
Designated priority class
IPTosMap[1:0]
0
1
2
3
4
5
6
7
00
C0
C0
C1
C1
C2
C2
C3
C3
01
C1
C2
C2
C2
C3
C3
C3
C3
10
C1
C1
C2
C2
C2
C3
C3
C3
IPTosMap[1:0]
TxData3_[6:5]
11
C0
C1
C1
C2
C2
C3
C3
C3
Selects one of four mappings for the 8 level user_priority extracted
from the frame’s VLAN Tag to the 4 level priority offered by TC9208M
(C0, C1, C2, C3 – class 0, 1, 2, 3 of service)
Designated priority class
VLANPrMap[1:0]
0
1
2
3
4
5
6
7
00
C0
C0
C1
C1
C2
C2
C3
C3
01
C1
C0
C0
C1
C2
C2
C3
C3
10
C0
C0
C0
C1
C1
C2
C3
C3
VLANPrMap[1:0] TxData3_[3:2]
11
C2
C0
C1
C2
C3
C3
C3
C3
Confidential.
21/53
August 1, 2003
Copyright © 2003, IC Plus Corp.
TC9208M-DS-R06