Hardware connection of FMU microprocessor pins and external port connectors

The Ardupilot compatible HW design is a very interesting topic about interoperability, autonomous drive vehicle design and real time processing, so I find the project very exiting.
For this reason I’m studying the FMU controller design, based on the FMUV6x specifications to understand its HW functions and configuration. I got to several design documentation but I think there could be some missing information about the standard design specification.

Indeed I’m struggling to understand the following assignment and electrical connections of the standard connection ports:

  • FMU_BOOTLOADER: Is it directly connected to the BOOT_0 pin of the FMU microprocessor?

  • FMU_RST_REQ: Is it directly connected to the RESET pin of the FMU microprocessor?

  • ETH_RESET: We think it is not connected because the Ethernet protocol is still not supported.

Furthermore the microprocessor pinout shows the following PIN that we don’t know how they are connected. I think their function is related to the vendor HW version, but no information about how do they are connected is provided. Is there a logic level assignement rule for that PINs ?


Finally, I can’t find a specification of the TRACECLK PIN PORT connection. How does it is connected to the FMU microprocessor?


Thanks in advance for your time and hope this topic may improve the understanding on how the HW and the FW together.