VojislavM
commented
7 years ago Specifics in design:
- USB 2 and USB 3 are used
- HUB can be restarted from the RPi CM GPIO6 PIN
- nTRST pin This active low pin functions as the JTAG test port reset input. Note: This pin should be tied high if it is not used.
- TEST3 PIN this pin must always be connected to VDD33IO for proper operation.
- AUTOMDIX PIN Determines the default Auto-MDIX setting. 1 = Auto-MDIX is enabled.
- EXRES Used for the internal bias circuits. Connect to an external 12.4K 1.0% resistor to ground.
- USBRBIAS Connect to an external 12K 1.0% resistor to ground.
Because Raspberry Pi compute module has no Ethernet pins additional "bridge" is needed. Best solution for this is widely used LAN9512 USB 2.0 Hub and 10/100 Ethernet Controller. It will connect to the Raspberry Pi CM USB. On the other side ti will have one Ethernet connector RJ45 with the PoE pins and two USB A female connectors. One will not be populated, because Koruza unit needs only one.
LAN9512 HUB will not be directly connected to the RPi CM. It will be connected thru the USB MUX FSUSB42UMX because the RPi CM has option to be booted form the USB, and this is something Koruza units could possible use. If unnecessary USB connector should not be populated.