CM3这个内核是大小端可配置的： The processor contains a configuration pin, BIGEND, that enables you to select either the little-endian or BE-8 big-endian format. This configuration pin is sampled on reset. You cannot change endianness when out of reset. STM32是固定配置为小端的：RM0008 Reference manual The bytes are coded in memory in Little Endian format. The lowest numbered byte in a word is considered the word’s least significant byte and the highest numbered byte the most significant.
