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14. Circuit Example
14.1 Reset In
For the reset pin J3.16, a reset button to pull this pin to ground to reset core board is necessary,
the ESD component and bypass capacitor is used according to the actual design, a resistor pull up
to power supply is installed on SOM board, so not any resistors pull up/down is need.
Picture14.1 Reset In
14.2 Power Key
For the power pin J3.14, assert this pin to ground to indicate a power event. Long press to turn off
the SOM board and short press to turn on the SOM board. The ESD component and bypass
capacitor is used according to the actual design, a resistor pull up to power supply is installed on
SOM board, so not any resistors pull up/down is need.
Picture14.2 Power Key
14.3 Boot Mode
The power used for pull up resistors for boot configuration should source from SOM board to
avoid any unpredictable failure. The power output pins are J3.21 and J3.23.
The following figure shows to boot up from eMMC on SOM board.
Picture14.3 Boot up from the eMMC on SOM
If the designer desires to boot the board up from any other storage device, please refer the
following table to change the boot-up configuration, further information please refer to
Mini Applications Processor Reference Manual.
Caution
:
The pull-up resistor of boot configuration should be connected to NVCC_3V3 from J3.
On-board eMMC: Connected to uSDHC3 8 bit
4.
7K
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
4.
7K
NI
4.
7K
NI
4.
7K
NI
4.
7K
SAI1_TXD3
SAI1_TXD1
SAI1_TXD0
SAI1_RXD0
SAI1_TXD6
SAI1_TXD7
SAI1_TXD2
SAI1_RXD4
CFG1
CFG0
CFG4
CFG3
CFG2
CFG6
CFG5
CFG9
CFG8
CFG7
CFG12
CFG11
CFG10
CFG14
CFG13
CFG15
NVCC_3V3
SAI1_RXD2
SAI1_TXD4
SAI1_TXD5
SAI1_RXD1
SAI1_RXD5
SAI1_RXD3
SAI1_RXD6
SAI1_RXD7
Boot Config
