Question about send_packet in ethernet MAC lib 3.0.1

[gerrykurz]

The send_packet function has a parameter called ifnum which from the documentation is

ifnum The index of the MAC interface to send the
packet Use the ETHERNET_ALL_INTERFACES define to send to all interfaces.

How do I get the index of a MAC interface?

In my application, I am using three instances of the MAC interface.

[srinie]

Hi,
I do not ve a feedback on this, but am curious to know a couple of things.

Which version of mac you are using (excluding the rgmii one since it uses 1 tile for it)?
(should be raw mii or 100 mbps standard one)?


From the task diagram, the application connects to an instance of MAC using ethernet_tx_if. Not fully clear from the documentation whether the application need to handle data between multiple MACs or mii buffering takes care of this.

============================

My understanding is that the current state of the code does not seem to use this!!!

inline void send_packet(client ethernet_tx_if i, char packet[n], unsigned n,
unsigned ifnum) {
i._init_send_packet(n, ifnum);
i._complete_send_packet(packet, n, 0, ifnum);

---------------

case i_tx[int i]._complete_send_packet(char data[n], unsigned n,
int request_timestamp,
unsigned dst_port):
memcpy(txbuf, data, n);
i_mii.send_packet(txbuf, n);
// wait for the packet to be sent
mii_packet_sent(mii_info);
break;

==============

[gerrykurz]

I am using one instance of the real time mac and two instances of the regular 100 mbps.

And yes, I am a bit confused about the ifnum parameter and how it may or may not apply to multiple mac instances.

The only example in the documentation is using the ETHERNET_ALL_INTERFACES define for this parameter but they don't say what this would do in a multiple mac configuration.

[gerrykurz]

Here is a bit more information about my application.

All three mac instances are running on different tiles. I have four tiles (two L16 parts) in my application.

[gerrykurz]

Here is the answer to this question from XMOS:

The ifnum parameter is not currently used but is reserved for potential use in future versions of the MAC.

[Dukuu]

Here is the answer to this question from XMOS:

The ifnum parameter is not currently used but is reserved for potential use in future versions of the MAC.

Thanks for that answer! I was looking through the code, where this "ifnum" is used, and did not find. Great, that you answered this here. Sad, that it is not described in any docs.

[peter]

It's worth noting that there was a dual-port version of the ethernet MAC that was used for the Daisy Chain AVB. This support is not in the latest version of the ethernet MAC, but that is the reason that the argument is in the API - so it doesn't have to change to support multi-ported MAC.

In the dual-port MAC the "ifnum" argument could be used to control which interface a packet was sent on. Either a specific interface or all interfaces in the case of a broadcast.