实现STM8L152串口3数据的收发，亲测可以正常使用
资源文件列表
B07_USART3/checkres.spy , 292
B07_USART3/Debug/checkres.spy , 292
B07_USART3/Debug/main.ls , 8663
B07_USART3/Debug/main.o , 30110
B07_USART3/Debug/stm8l_demo.elf , 27685
B07_USART3/Debug/stm8l_demo.lkf , 2270
B07_USART3/Debug/stm8l_demo.map , 34781
B07_USART3/Debug/stm8l_demo.s19 , 1250
B07_USART3/Debug/stm8l_demo.sm8 , 29456
B07_USART3/Debug/stm8_interrupt_vector.ls , 5477
B07_USART3/Debug/stm8_interrupt_vector.o , 2781
B07_USART3/main.c , 2966
B07_USART3/Release/stm8l_demo.lkf , 2292
B07_USART3/stm8l_demo.dep , 477
B07_USART3/stm8l_demo.pdb , 896
B07_USART3/stm8l_demo.stp , 12352
B07_USART3/STM8L_Demo.stw , 209
B07_USART3/STM8L_Demo.wdb , 23298
B07_USART3/STM8L_Demo.wed , 23463
B07_USART3/stm8l_demo_Programmer/stm8l_demo_STVP.stp , 585
B07_USART3/stm8l_demo_Programmer/stm8l_demo_STVP_OPTION BYTE.hex , 133
B07_USART3/stm8_interrupt_vector.c , 1954
B07_USART3/TAGS.txt , 1682
B07_USART3/TAGS_Filelist.txt , 225
B07_USART3/简要说明.txt , 286