HOW TO ENNABLE THE REMANNING MAC2 & MAC3 OF ETH IN STM32H745 DISCOVERY BOARD

[syed1]

HI..,

I am using the STM32H745 DISCOVERY BOARD in that i am working on ETHERNET SECTION in that my  aim is to configure the FOUR DIFFERENT MACS for the stm discovery board. Now out of four MACS i have configured the two  macs independently .The issue is i am unable to configure the remanning two macs although i have used these registers for the configuration of the macs  (ETH_MACAxHR) & (ETH_MACAxLR).AM I missing any other thing in the configuration of mac or any other particular register related to enable of the remaining macs pls let me know .

Thanks & regard:

syed1.

[ASEHST]

Hello @syed1 ,

To assist you more effectively, could you please provide us with the details of your four MAC addresses configuration?

With Regards

[syed1]

Hello @ASEHST,

According to RM0399, STM32h745 controller supports 4 independent MACs I have added a snip for reference

It says by default, the MacAddr0 is enabled. We were successfully able to transmit and receive frames from MacAddr0. 

In order to transmit and receive from MacAddr1 we have enabled the AE bit in ETH_MACxHR (x=1), then we have modified the SARC[2:0] fields of ETH_MACCR to 111b. With this we were able to transmit and receive from MacAddr1.

But there is no provision given to insert/replace the source address (SA) of MacAddr2 and MacAddr3 into Tx packets.

Ultimately, we want to use all 4 MACs in our configuration. Is it possible to run all MACs simultaneously?

As mentioned in the Note, we have to change the source address before transmitting every packet from the controller.

Could you please help us?

[Pavel A.]

> But there is no provision given to insert/replace the source address ....

> As mentioned in the Note, we have to change the source address before transmitting every packet

So just do this? Disable automatic insertion of SA and add the desired SA manually?

[syed1]

hello @Pavel A. 

In order to transmit and receive from MacAddr2 we have enabled the AE bit in ETH_MACxHR (x=1), but the issue is as we can see there is no provision given in the SARC[2:0] fields of ETH_MACCR  for the MacAddr2  and MacAddr3 .

As it says in RM0399 page N0:3112  ,it shows that 010:the MAC inserts the content of the MAC Address 0 registers and  110: the MAC inserts the content of the MAC Address 1 registers  .so where are the  MAC insert contents of the MAC  Address 2 and MAC Address3? could you please elaborate this .