RT-Thread/rt-thread: https://github.com/RT-Thread/rt-thread.git @ deca72a34159e885e4e309c258c52f4eaeca0905

chenchaoqun@rt-thread.com bb8e89e851 【串口】宏定义对应增加		7 anni fa
..
applications	80a21100b3 remove uart rx code	8 anni fa
asflib_config	189c999f8e add atmel SAM D21 bsp support	8 anni fa
board	189c999f8e add atmel SAM D21 bsp support	8 anni fa
sam_d2x_asflib	62058e18fe [bsp][samd21] update scons script.	7 anni fa
README.txt	84f0d9f988 Update README.txt	8 anni fa
SAM_D2X_RTT.sct	5b1235f5f5 add scons cmd build	8 anni fa
SConscript	189c999f8e add atmel SAM D21 bsp support	8 anni fa
SConstruct	189c999f8e add atmel SAM D21 bsp support	8 anni fa
project.uvprojx	0f3563fd64 [BSP] Update project files	8 anni fa
rtconfig.h	bb8e89e851 【串口】宏定义对应增加	7 anni fa
rtconfig.py	62058e18fe [bsp][samd21] update scons script.	7 anni fa
template.uvprojx	189c999f8e add atmel SAM D21 bsp support	8 anni fa

		
				README.txt
			
				使用SAMD21-Xplained-Pro开发板
scons:
  scons
  scons --target=mdk5
demo代码演示了串口、外部中断、RTC低功耗唤醒