SMARC-sAMX7 User Guide. Rev. 1.9
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6/
Installation
6.1.
Boot Mode
The following table shows the possible boot sources on the carrier board defined in SMARC 2.0 spec:
Table 10: Boot Options on the carrier board
Carrier Connection
Boot Source
Supported on
sAMX7
BOOT_SEL2#
BOOT_SEL1#
BOOT_SEL0#
0
GND
GND
GND
Carrier SATA
No
1
GND
GND
Float
Carrier SD Card From U-Boot
2
GND
Float
GND
Carrier eSPI
(CS0#)
From U-Boot
3
GND
Float
Float
Carrier SPI
(CS0#)
From U-Boot
4
Float
GND
GND
Module device
(NAND, NOR)
No
5
Float
GND
Float
Remote boot
(GBE, serial)
From U-Boot
U-Boot only supports booting from QSPI NOR flash because "boot from fuses" is defined per default.
6.2.
Configurable Watchdog
As no CPLD is available, the Watchdog must be used from the SoC. The WDOG features are listed below:
Configurable timeout counter with timeout periods from 0.5 to 128 seconds which, after timeout expiration,
result in the assertion of WDOG_RESET_B_DEB reset signal .
Time resolution of 0.5 seconds
Configurable timeout counter that can be programmed to run or stop during low-power modes
Programmable interrupt generation prior to timeout
The duration between interrupt and timeout events can be programmed from 0 to 127.5 seconds in steps of
0.5 seconds.
