MSC SM2S-IMX8M User Manual
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4.16
Boot-Options
Table 4-16: Boot Options Control Signal Description
Signal
Pin Type
Signal
Level
Pin on
i.MX8M
Pin name on
i.MX8M
Power
Tolerance
PU/PD
Description
BOOT_SEL0#
I OD
1.8V CMOS
M4
SAI5_RXD2
1.8V
PU 10k 1.8V
Input straps determine the module boot device.
Pulled up on Module. Driven by OD part on
Carrier.
(CPU GPIO3_IO23)
BOOT_SEL1#
I OD
1.8V CMOS
K5
SAI5_RXD3
1.8V
PU 10k 1.8V
Input straps determine the module boot device.
Pulled up on Module. Driven by OD part on
Carrier.
(CPU GPIO3_IO24)
BOOT_SEL2#
I OD
1.8V CMOS
D3
SAI3_MCLK
1.8V
PU 10k 1.8V
Input straps determine the module boot device.
Pulled up on Module. Driven by OD part on
Carrier.
(CPU GPIO5_IO02)
FORCE_RECOV#
I OD
1.8V CMOS
N4
SAI5_RXFS
1.8V
PU 10k 1.8V
always on
Pulled up on Module. Driven by OD part on
Carrier.
(CPU GPIO3_IO19)
TEST#
I OD
1.8V CMOS
n.a.
n.a.
1.8V
PU 10k 1.8V
Active low signal for test mode activation.
Pulled up on Module. Driven by OD part on
Carrier.
If the
SMARC™ module is powered up with VIN_PWR_BAD# left floating and RESET_IN# left floating, the module boots from selected boot device.
If FORCE_RECOV# signal is pulled low at carrier, the module boots via USB-Client Mode (this feature is only intended for recovery and requires
dedicated software from NXP).For normal operation do not pull FORCE_RECOV# signal low.
TEST# signal is checked for primary boot device selection (primary boot device selection defines the device in which ROM code expects SPL and U-
BOOT code). With inactive test mode the module loads the boot loader from eMMC and checks the BOOT_SEL signals for operating system location.
The i.MX8M SoC supports recovery devices. If primary boot device fails, the module will always try to boot from SD-Card. This means in detail, that if
the TEST# signal is not pulled low and eMMC does not contain valid boot code, the carrier SD-Card is booted. This is unintended behaviour (but