DM8148 vs DM8168 EMAC

Krzysztof Mlodozeniec1

Hi,

I would appreciate some clarification on the number of EMACs available in DM8148 and DM8168. Parametric search indicates that 8148 has one EMAC, and 8168 has two. However, both datasheets state that there is a three port EMAC switch built into each device. One of the ports is connected internally to the device, the other two are available externally. This is the bit which I don't understand. How many individual networks can each device support? How many Ethernet interface would be present in Linux with each of these devices?

Kind regards,
Krzysztof

over 12 years ago

0 Vladimir-XID over 12 years ago

TI__Genius 11470 points

Hello Krzysztof,

Please, refer to: http://processors.wiki.ti.com/index.php?title=TI81XX_PSP_Ethernet_Switch_User_Guide

Note:

http://processors.wiki.ti.com/index.php?title=TI81XX_PSP_Ethernet_Switch_User_Guide#Compiling_kernel

and

http://processors.wiki.ti.com/index.php?title=TI81XX_PSP_Ethernet_Switch_User_Guide#Bringing_Up_interfaces

Both DM814x and DM816x EVMs has 2 Ethernet ports and you can see them and use them in the same time from Linux. On DM816x kernel configuration probably is with dual EMAC by default.

Vladimir

0 Vladimir-XID over 12 years ago in reply to Vladimir-XID

TI__Genius 11470 points

PS: Also check the DM814x TRM: "9.1.8 3PSW Ports" for the third port:

"
Ethernet Subsystem has 3 Ports. Port 0 is the Host port (internal to the Subsystem). Ports 1 and 2 are the
external ports connected to G/MII, RGMII, or RMII interfaces as per the interface selected.
"
BR

Vladimir

0 Krzysztof Mlodozeniec1 over 12 years ago in reply to Vladimir-XID

Prodigy 50 points

Hi Vladimir,

Many thanks for the links, it did help me understand the EMAC situation a little better. However, I am still not sure with regards to two EMACs being available on DM8168. Does that mean DM8148 leave the factory preprogrammed with one unique MAC address assigned by TI and DM8168 comes with two?

Kind regards,
Krzysztof

0 Vladimir-XID over 12 years ago in reply to Krzysztof Mlodozeniec1

TI__Genius 11470 points

Krzysztof,

Features section [1.1] of the DM814x datasheet says "Dual Port Ethernet". DM814x should have 2 unique MAC addresses just like DM816x does.

Vladimir

0 Krzysztof Mlodozeniec1 over 12 years ago in reply to Vladimir-XID

Prodigy 50 points

Hi Vladimir,

Many thanks for the suggestions, but I am still not sure whether this is correct. Below is a parametric search results and as shown 8148 is listed with 1x EMAC and 8168 has 2. I need to know what does that actually mean?

Kind regards,
Krzysztof

0 Vladimir-XID over 12 years ago in reply to Krzysztof Mlodozeniec1

TI__Genius 11470 points

Hi Krzysztof,

Both Ethernet interfaces of DM814x EVM work properly in the same time, I've verified that personally. However I'll try to gather info about the above parametric list and if I have something, I'll post it here.

BR
Vladimir

0 Vladimir-XID over 12 years ago in reply to Vladimir-XID

TI__Genius 11470 points

Hi Krzysztof,

DM814x has one 3-port 10/100/1000 switch (only two of them are external ports) and DM816x has two 10/100/1000 Ethernet MACs. That was confirmed.

Thank you.

Vladimir

Processors

Processors forum

DM8148 vs DM8168 EMAC