I was wondering if the STM microcontroller onboard is necessary for the two PHY’s to function. I would like some insight to exactly the microcontroller does. Would it be possible for the 2 PHY’s to function as an SPE convertor autonomously, without the MCU drawing power?
Also, the SPEBlox must be configured as master or slave. Is the MCU required for that functionality?
On SPEBlox Rev F, the STM32 configures both PHYs at startup, including applying the master/slave selection. Once configured, the PHYs handle Ethernet traffic directly, without the MCU processing the packets.
If your aim is to reduce power consumption, removing the MCU would likely save very little. It runs at approximately 2.1 MHz, and we estimate its own consumption to be milliwatt-scale, excluding LED loads, compared with around 1.4 W for the complete board.
The standard board still needs that startup configuration, and operating with the MCU unpowered hasn’t been validated.
Are you targeting a particular power budget, or mainly asking whether the PHYs need continuous MCU involvement?