ip178a ETC-unknow, ip178a Datasheet - Page 21

• Manufacturer Part Number: ip178a
• Description: 8-port 10/100 Ethernet Integrated Switch
• Manufacturer: ETC-unknow

Automatic MDI/MDI-X configuration
IP178A supports MDI/MDI-X function if the function is
enabled. The RX and TX pairs will be corrected
automatically. That is, IP178A can be connected to
another devices with either crossover cable or
non-crossover cable.
When a cable is plugged, IP178A looks for NLP, FLP or
MLT3 signals to make sure if the receive path is correct.
If IP178A finds nothing in the receiving path, it crosses
over the RX and TX pairs and examines the inputs again.
The process will go on until IP178A sees a stable NLP,
FLP or MLT3 signals. The process starts prior to the
auto-negotiation.
The MDI/MDI-X function needs specific type of
transformer. The PCB for previous version of IP178A
also supports MDI/MDI-X function if the specific type of
transformer is adopted.
CoS
IP178A supports two type of CoS. One is port base
priority function and the other is frame base priority
function. A high priority packet will be queued to the high
priority queue to guarantee its faster delivery. IP178A
supports two levels of priority queues.
The packets received from port 6 or port7 are handled as
high priority frames if the port base priority is enabled. It
is enabled if pin p6_7_high is pulled high or the bit
02H[14] of EEPROM register is set. The setting in
register takes precedence of the setting on pins.
Preliminary, Specification
IP178A-DS-P05
Sep. 09, 2002
subject to change without notice
21
IP178A examines the specific bits of VLAN tag and
TCP/IP TOS/DS for priority frames if the frame base
priority is enabled. The packets will be handled as high
priority frames if the value of VLAN tag or TCP/IP
TOS/DS field meets the high priority requirement. It is
enabled if pin Cos_en is pulled high or EEPROM register
02H[15] is set. The setting in register takes precedence
of the setting on pins.
VLAN
IP178A supports port base VLAN functions if the function
is enabled. It separates IP178A into some groups
(VLAN). A port is limited to communicate with the ports
within the same group (VLAN). Frames will be limited in
a VLAN and will not be forwarded to other VLANs. A port
can be assigned to one or more VLANs. The members
(ports) of a VALN are assigned by programming the
content of EEPROM register 07H~0AH.
The VLAN function can be enabled even if there is no
EEPROM. IP178A supports an easy way to utilize VLAN
function without EEPROM. A specific configuration of
VLAN is adopted if pin VLAN_ON is pulled high. It is
benefit in a router application that an individual LAN port
shares a WAN port but doesn’t communicate each other.
The VLAN group in this mode is illustrated in the pin
description of VLAN_ON.
The VLAN function is enabled if pin VLAN_on is pulled
high or filling the content of EEPROM register 07H~0AH.
The setting in register takes precedence of the setting on
pins.
(Advance Version)
IP178A