Boot Order - Cherry RINGNECK SOM-PX30-uQ7 User Manual

Note: The fan is only necessary in high ambient temperatures. Under normal conditions, the RINGNECK
SOM-PX30-uQ7 operates passively cooled.

3.5 Boot Order

The used boot order of the RINGNECK SOM-PX30-uQ7 module depends on the value of the BIOS_DISABLE#
signal. On the Haikou baseboard, this signal can be set using a slider switch (BOOT SW), with the two positions
labeled Normal Boot, and BIOS Disable.
As shown in the table below, the BIOS Disable position disables the eMMC storage device:
If no bootloader is found on any storage device, the RINGNECK SOM-PX30-uQ7 module will go into USB loader
mode, showing up as a USB device on the USB-OTG port.
The electrical state of the BIOS_DISABLE# signal for both slider positions is shown below:
RINGNECK SOM-PX30-uQ7 User Manual
© Cherry Embedded Solutions GmbH
Fig. 3.3: Fan connector
Normal Boot
1 eMMC storage
2 SD card
3 USB loader
BIOS_DISABLE# signal
Slider Position
Normal Boot Floating (on-module pull-up to 3.3V)
BIOS Disable GND
BIOS Disable
SD card
USB loader
v1.3.1
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