I would like to put the processor to sleep while keeping the Ethernet active. I don’t control software on the other end and therefore can’t send a WoL packet, but LAN8742, for instance, has “Perfect DA Detection” which can interrupt if an Ethernet frame is received. Can the iMX6ULL go to S2RAM and then wakeup on this interrupt? Will the wakeup be fast enough so that it doesn’t affect TCP?
Hello @user45769
we will check with the R&D team on this topic. It not sure if the architecture is optimized for that.
What are your main goals? to save power?
Best Regards,
Matthias
What are your main goals? to save power?
Yes, its battery operated. Another option would be to use ENC28J60
The Micrel Ethernet PHY KSZ8041 does not even support WOL/Magic packet detection. However, the i.MX 6ULL MAC would support WOL/Magic packet detection.
Wake on general Ethernet activity may only be possible with an external solution as you propose hooking up resp. INT# pin to a wake-up capable GPIO.
Please note that Ethernet itself usually requires more than half a Watt to operate. The module in Idle is well below 1 Watt… Compared to full-fledged x86 systems the relative power savings are rather small with Arm-based Embedded Systems since the module is already very low power (relative to Ethernet or complete x86 systems…).