Quantcast
Channel: Raspberry Pi Forums
Viewing all articles
Browse latest Browse all 5001

General • Re: Ethernet MAC support with RP2350 ?

$
0
0
can 1 or 2 Ethernet MACs be supported on RP2350?
I assume your question to mean "can itself RP2350 perform the functions of an Ethernet MAC", ie. provide Ethernet interface(s) with just an external PHY.

RP2040 can already support a 10/100 Ethernet interface using just an external PHY and the MAC in software, using PIO for the interface. In fact it has sufficient I/O resources (pins, PIO units, DMA channels) to support two of them, but a two-PHY configuration is unlikely to be useful since there's so little resource left over to do anything with the 100Mbit/sec of data arriving.

I don't see that RP2350 changes the situation very much. It has a bit more CPU power, but not enough to make a huge difference. The main new peripheral feature is the HSTX, but that's transmit-only: it might perhaps be useable for Ethernet transmit, but since receive performance is normally the limiting factor that doesn't help much.

Probably the RP2350's higher maximum clock rate will be useful: RP2040 has to be under-clocked to 100MHz in order to generate a 50MHz clock to the PHY; probably the RP2350 can run at full speed with a divide-by-three for the PHY clock, but I haven't proven that yet.

My interest has been in RMII PHYs (2 data bits per direction, 50MHz); you could also potentially use the older standard MII (4 bits per direction, 25MHz) - with the extra pins available on RP2350B that might become more attractive, though other aspects of the interface are simplified with RMII and more tricky with MII.

Statistics: Posted by arg001 — Fri Aug 09, 2024 12:55 pm



Viewing all articles
Browse latest Browse all 5001

Trending Articles