Interfacing (DSI, CSI, I2C, etc.) • Re: Regarding changes in Ethernet LED behavior due to dtparam changes in config.txt. (Compute Module 4)

Thank you for your reply.

Checking the CM4 datasheet(https://datasheets.raspberrypi.com/cm4/ ... asheet.pdf), the behavior of each LED is described as follows.

Ethernet_nLED1
Active-low Ethernet speed indicator (3.3V signal): typically a yellow LED is connected to
this pin. A low state indicates the 1Gbit or 10Mbit link: IOL = 8mA @ VOL < 0.4V

Ethernet_nLED2
Active-low Ethernet speed indicator (3.3V signal): typically a yellow LED is connected to
this pin. A low state indicates the 1Gbit or 100Mbit link: IOL = 8mA @ VOL < 0.4V

Ethernet_nLED3
Active-low Ethernet activity indicator (3.3V signal): typically a green LED is connected to
this pin. IOL = 8mA @ VOL < 0.4V

I wrote the following statement in config.txt and confirmed the LED operation.
The CM4IO board(https://datasheets.raspberrypi.com/cm4i ... asheet.pdf) is used to check ethernet LED lighting colors.
The ethernet green LED on the IO board is controlled using the Ethernet_nLED2 signal line.
My expectation was that since eth_led0 was set to 1, green LED would turn on when the communication speed was 1Gbit or 100mbit and turn off when the speed was 10mbit, but in fact it turned on at all speeds, which is different from the behavior described in the Datasheet.

I want the CM4 signal lines Ethernet_nLED1,2,3 to behave as per the datasheet, is there any way to achieve this?

Statistics: Posted by kuma345213 — Thu Jun 13, 2024 3:21 am

---