Kontron SMARC-sA3874i - Manual (Page 76)

76 www.kontron.com
User’s Guide
8.2 BOOT Selection
ULP-COM sA3874i module can be booted from various devices or modules. The boot selection is done in the
carrier board by either floating the ULP-COM BOOT_SELx# pins or tying them to GND per the table below.
Currently, only Carrier SD Card boot is supported.
BOOT_SEL2# BOOT_SEL1# BOOT_SEL0# Boot Source
FLOAT GND FLOAT Serial Port 1
FLOAT FLOAT FLOAT Module SPI
GND GND FLOAT Carrier SD Card
FLOAT GND GND Module eMMC
Caution! A BOOT_SELx# combination not contained in the table above is not valid. The ULP-COM sA3874i module
will default to boot from the Module eMMC Flash if an invalid combination is selected.
The ULP-COM sA3874i boot selection is provided from the module CPLD as a 4bit selection to the TI Cortex A8
SoC. The CPLD provides a 3bit selection from the carrier as shown in the table above
Figure 17: Boot Selection Strap Implementation
E
D
G
E
F
IN
G
E
R
(J
3
)
CPLD
(U20)
SITARA CPU
(U10)
P123
P124
P125
K11
J10
J11
F10
C7
G10
B8
Y28
V27
W27
U26
BTMODE[1]
BTMODE[2]
BTMODE[3]
BOOT_SEL0#
BOOT_SEL1#
BOOT_SEL2#
BTMODE[0]
BTMODE[4]
E10 V26