PROCESSOR-SDK-AM437X: Relationship between the EMAC/CPSW port and an IP addresses

Marcio Borges

Expert 1950 points

Part Number: PROCESSOR-SDK-AM437X

Hello,

Please could you explain the "switch" concept behind EMAC/CPSW.

Does EMAC/CPSW work like a network switch (3COM, DLINK, etc.)?

Is there a relationship between the EMAC port and the IP address configured with CfgAddEntry?

For instance, suppose the software calls CfgAddEntry with tag=CFGTAG_IPNET and item=1 to configure 10.16.3.170 and then calls CfgAddEntry again with tag=CFGTAG_IPNET and item=2 to configure static IPs 192.168.0.2.

Does a message from 10.16.3.170 is always sent (compulsorily) through the eth0 or EMAC can send it through any eth port?

Does eth0 port only receive packets for 10.16.3.170 or any eth port can receive packets for 10.16.3.170?

Best Regards,

Marcio

over 2 years ago

0 Ashwani Goel over 2 years ago

TI__Mastermind 27270 points

Hi Marcio,

Thanks for your query.

I will get back to you soon. Meanwhile you can refer section " 7.1. Dual EMAC and Switch" on below page

Marcio Borges said:
Please could you explain the "switch" concept behind EMAC/CPSW.

https://software-dl.ti.com/processor-sdk-rtos/esd/docs/latest/rtos/index_pru_icss_fw.html?highlight=switch#switch

Best Regards

Ashwani

0 Marcio Borges over 2 years ago in reply to Ashwani Goel

Expert 1950 points

Hello Ashwani,

I´ve looked the document and I have not found the relationship between the IP configuration (CfgAddEntry) and the eMAC/CPSW ports.

Did you have more info?

Best regards,

Marcio

0 Ashwani Goel over 2 years ago in reply to Marcio Borges

TI__Mastermind 27270 points

Hi Marcio,

Can you please provide more details about your use case ?

Which SDK / PDK version you are referring here ?

Best Regards

Ashwani

0 Ashwani Goel over 2 years ago

TI__Mastermind 27270 points

Marcio Borges said:
Does EMAC/CPSW work like a network switch (3COM, DLINK, etc.)?

Yes, we support CPSW switch on AM437x board.

https://www.ti.com/lit/an/sprach5a/sprach5a.pdf?ts=1676369651394&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FPROCESSOR-SDK-AM437X

Best Regards

Ashwani

0 Ashwani Goel over 2 years ago

TI__Mastermind 27270 points

Marcio Borges said:
Is there a relationship between the EMAC port and the IP address configured with CfgAddEntry?

IP address assignment come into picture with TCP/IP layer which is handled in NDK layer in our pdk.

https://software-dl.ti.com/processor-sdk-rtos/esd/docs/latest/rtos/index_Foundational_Components.html?highlight=cpsw#ndk-overview

Best Regards

Ashwani

0 Marcio Borges over 2 years ago in reply to Ashwani Goel

Expert 1950 points

Hello,

We work in dual-port mode, that is, 2 different MACs and 2 different IPs.

CfgAddEntry is utilized to configure NDK with IP addresses.

Is there a relationship of ownership between the IPs configured via CfgAddEntry and an EMAC port?

Is it true to say that the first call to CfgAddEntry owns EMAC port 1 and the second call owns EMAC port 2?

If the first call to CfgAddEntry sets 10.16.3.170 and the second call sets 192.168.0.2. Does a message to 10.16.3.170 will always be received (compulsorily) through the EMAC port 1?

I don´t see any reference on the documentation.

Best regards,

+1 Ashwani Goel over 2 years ago in reply to Marcio Borges

TI__Mastermind 27270 points

Sorry for delay in response as I was out for some days.

Marcio Borges said:
We work in dual-port mode, that is, 2 different MACs and 2 different IPs.

For this use case please refer below docs

https://software-dl.ti.com/processor-sdk-rtos/esd/docs/latest/rtos/index_pru_icss_fw.html#dual-emac-and-switch

In short:

We have 2 physical ports (Port1, Port2) having 2 MAC addresses (MAC1, MAC2) should be mapped to 2 IP addresses (IP1, IP2) respectively.

Packets coming for Destination Address = IP1 will be received by MAC1 / Port1.

Best Regards

Ashwani

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PROCESSOR-SDK-AM437X: Relationship between the EMAC/CPSW port and an IP addresses