SBC-C31
SBC-C31 User Manual - Rev. First Edition: 1.0 - Last Edition: 1.0 - Author: A.R. - Reviewed by D.T. - Copyright © 2021 SECO S.p.A.
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RST: Reset Input, active Low signal. Electrical Level +3.3V_ALW with 1.5k pull-up resistor
ONOFF: Power On/Off Input, active Low signal
3.3.17
SPI Connector
Onboard, connector CN6 carries out signals related to SPI interface #1 from RK3399
processor.
For this purpose, a dedicated 4-pin Connector, Type MOLEX p/n 53398-0571 or equivalent
is provided.
Mating connector: MOLEX 51021-0500 receptacle with MOLEX 50079-8000 female crimp
terminals.
SPI1_MISO: SPI Master Input Slave Output, input signal, electrical level +3.3V_RUN
SPI1_MOSI: SPI Master Output Slave Input, output signal, electrical level +3.3V_RUN
SPI_CLK: SPI Serial Clock, electrical level +3.3V_RUN
SPI1_CS0#: SPI chip select, output signal, active low, electrical level +3.3V_RUN. This signal is activated when this interface is used as communication with external
devices
3.3.18
RECOVERY MODE connectors
Two connectors on-board can be used to enter in recovery mode firmware download mode.
Both connectors are 2-pin, pitch 1mm, type Joint Tech P/N A1001WV-S-2P or equivalent. Mating connector Joint Tech A1001H-2P-1 with Joint Tech
A1001-TPE-B female crimp terminals
The first connector allows entering in Maskrom Mode
Maskrom is a special internal firmware of RK3399 that runs Rockusb driver automatically when there
is no bootable firmware found on on-board storage such as SPI flash, eMMC or microSD card.
The second connector, CN58, allows entering in the firmware download mode.
When the key is pressed and the level of ADKEY_IN is kept low at system power-up, RK3399 will enter firmware
download mode.
When PC recognizes the USB device, the key is released, then the firmware can be downloaded to the SoC.
This functionality is not supported at the moment and is under development.
SPI Connector CN59
Pin Signal
1
SPI1_MOSI
2
SPI1_MISO
3
SPI_CLK
4
SPI1_CS0#
5
GND
Maskrom key CN57
Pin Signal
1
Maskrom_Key
2
GND
Recovery mode Key CN58
Pin Signal
1
Adkey_IN
2
GND