Usb_Boot - Quectel SG865W Series Hardware Design

NFC_SE_SPI8_MISO
NFC_SE_SPI8_MOSI
SENSOR_SPI_CLK
SENSOR_SPI_CS
SENSOR_SPI_MOSI
SENSOR_SPI_MISO

4.19. USB_BOOT

USB_BOOT is an emergency download interface. Pull it up to VREG_S4A_1V8 when booting, the
module can enter the emergency download mode. There is an emergency option when failures such as
abnormal start-up or running occur. For the convenient firmware upgrade and debugging in the future,
reserve this pin. The reference circuit design is shown below.
SG865W_Series_Hardware_Design
182 DI
176 DO
89 DO
95 DO
78 DO
84 DI
USB_BOOT
Module
Figure 27: Reference Design for USB_BOOT
NFC SE SPI8 master-in slave-out
NFC SE SPI8 master-out slave-in
SPI clock for external sensor
SPI chip select for external sensor
SPI master-out slave-in for external sensor
SPI master-in slave-out for external sensor
VREG_S4A_1V8
S1
R1
10K
Smart Module Series
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