THEMIS
THEMIS User Manual - Rev. First Edition: 1.0 - Last Edition: 2.2 - Author: A.R. - Reviewed by S.R. -Copyright © 2022 SECO S.p.A.
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Debug UART Connector
Onboard, connector CN39 carries out signals related to Debug Serial Port, which is managed by NXP i.MX8 UART3
internal controller, with signals available at TTL level. This interface can be used for the debugging of the processor.
For this purpose, a dedicated 4-pin Connector, Type MOLEX p/n 53398-0471 or equivalent is provided. Mating
connector: MOLEX 51021-0400 receptacle with MOLEX 50079-8000 female crimp terminals.
UART0_RX: UART #0 Receive data signal, electrical level +3.3V_RUN
UART0_TX: UART #0 Transmit data signal, electrical level +3.3V_RUN
Power and Reset buttons
THEMIS board is equipped with a Reset button (SW1) and a Power button (SW2), type C&K p/n KMR211G LFS.
When SW1 Reset button is toggled the board
’
s power section will be reset.
When SW2 Power button is toggled the board will turn on from off and respectively turn off from on.
Please be aware that the push button switches are available only on board in commercial temperature range, since they cannot sustain the full industrial temperature
range.
Power and Reset connector
Independently by the temperature range of the module purchased, it is always available an additional connector, CN56,
to allow use of external power and reset switches, this is a 5-pin Connector, type MOLEX 53398-0571 or equivalent.
Mating connector: MOLEX 51021-0500 receptacle with MOLEX 50079-8000 female crimp terminals.
iMX8_ON_OFF: input signal, pulled high internally with debounce function, when toggled the board will turn on from
off and respectively turn off from on.
RST_BTN: input signal, pulled high at +1.8V_RUN with a 70k
Ω
resistor, when toggled the board
’
s power section will be reset.
Boot Mode Selection jumper JP2
The onboard 2-way jumper JP2 can be used to select boot mode for the THEMIS module.
When the jumper is inserted in position 1-2, then the processor will search for the USB OTG connection to be
established, in order to download a program image to the chip.
When the jumper is inserted in position 2-3, the processor will continue to execute the boot code from the internal boot ROM.
Debug
UART
CN39
Pin
Signal
1
+3.3V_RUN
2
UART0_RX
3
UART0_TX
4
GND
Power and Reset CN56
Pin
Signal
1
+5V_RUN
2
GND
3
iMX8_ON_OFF
4
GND
5
RST_BTN
JP2 Jumper Boot mode
1-2
Serial download
2-3
Internal ROM
