Integration Guide

1. Characteristic Option
1.1 Boot mode
At startup, boot pins are used to select one out of three boot options:
• Boot from user Flash
• Boot from system memory
• Boot from embedded SRAM
The boot loader is located in system memory. It is used to reprogram the Flash memory by
using USART1(PA9/10), USART2(PD5/6), USB OTG FS in device mode (PA11/12) through
DFU (device firmware upgrade), I2C1(PB6/7), I2C2(PB10/3), I2C3(PA8/PB4),
SPI1(PA4/5/6/7), SPI2(PB1
2/13/14/15) or SPI3(PA15, PC10/11/12).
Low Boot from user Flash
BOOT0
High Boot from system memory / embedded SRAM
JP1
Header1x2
1
2
VDD_3V3
BOOT PIN
BOOT PIN
R1
10k
WM-N-BM-30 set the BOOT0 to GND, the Boot mode is Main Flash memory. When BOOT0
set to High, the BOOT mode is system memory.