实验三：按键查询（库函数）
..........................\drive
..........................\.....\key.c
..........................\.....\key.h
..........................\.....\led.c
..........................\.....\led.h
..........................\lib
..........................\...\inc
..........................\...\...\stm32f0xx_adc.h
..........................\...\...\stm32f0xx_cec.h
..........................\...\...\stm32f0xx_comp.h
..........................\...\...\stm32f0xx_crc.h
..........................\...\...\stm32f0xx_dac.h
..........................\...\...\stm32f0xx_dbgmcu.h
..........................\...\...\stm32f0xx_dma.h
..........................\...\...\stm32f0xx_exti.h
..........................\...\...\stm32f0xx_flash.h
..........................\...\...\stm32f0xx_gpio.h
..........................\...\...\stm32f0xx_i2c.h
..........................\...\...\stm32f0xx_iwdg.h
..........................\...\...\stm32f0xx_misc.h
..........................\...\...\stm32f0xx_pwr.h
..........................\...\...\stm32f0xx_rcc.h
..........................\...\...\stm32f0xx_rtc.h
..........................\...\...\stm32f0xx_spi.h
..........................\...\...\stm32f0xx_syscfg.h
..........................\...\...\stm32f0xx_tim.h
..........................\...\...\stm32f0xx_usart.h
..........................\...\...\stm32f0xx_wwdg.h
..........................\...\src
..........................\...\...\stm32f0xx_adc.c
..........................\...\...\stm32f0xx_cec.c
..........................\...\...\stm32f0xx_comp.c
..........................\...\...\stm32f0xx_crc.c
..........................\...\...\stm32f0xx_dac.c
..........................\...\...\stm32f0xx_dbgmcu.c
..........................\...\...\stm32f0xx_dma.c
..........................\...\...\stm32f0xx_exti.c
..........................\...\...\stm32f0xx_flash.c
..........................\...\...\stm32f0xx_gpio.c
..........................\...\...\stm32f0xx_i2c.c
..........................\...\...\stm32f0xx_iwdg.c
..........................\...\...\stm32f0xx_misc.c
..........................\...\...\stm32f0xx_pwr.c
..........................\...\...\stm32f0xx_rcc.c
..........................\...\...\stm32f0xx_rtc.c
..........................\...\...\stm32f0xx_spi.c
..........................\...\...\stm32f0xx_syscfg.c
..........................\...\...\stm32f0xx_tim.c
..........................\...\...\stm32f0xx_usart.c
..........................\...\...\stm32f0xx_wwdg.c
..........................\stm32f0
..........................\.......\stm32f0xx_conf.h
..........................\.......\system_stm32f0xx.c
..........................\user
..........................\....\JLinkLog.txt
..........................\....\JLinkSettings.ini
..........................\....\key.axf
..........................\....\key.crf
..........................\....\key.d
..........................\....\key.htm
..........................\....\key.lnp
..........................\....\key.map
..........................\....\key.o
..........................\....\key.plg
..........................\....\key.sct
..........................\....\key.tra
..........................\....\key.uvgui.Administrator
..........................\....\key.uvgui_Administrator.bak
..........................\....\key.uvopt
..........................\....\key.uvproj
..........................\....\key_Target 1.dep
..........................\....\key_uvopt.bak
..........................\....\key_uvproj.bak
..........................\....\led.crf
..........................\....\led.d
..........................\....\led.o
..........................\....\main.c
..........................\....\main.crf
..........................\....\main.d
..........................\....\main.o
..........................\....\startup_stm32f0xx.d
..........................\....\startup_stm32f0xx.lst
..........................\....\startup_stm32f0xx.o
..........................\....\startup_stm32f0xx.s
..........................\....\stm32f0xx_gpio.crf
..........................\....\stm32f0xx_gpio.d
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