TI是否 drivelib库文件，是否默认 M3启动后，用内部oscillator? 是否像ST那样默认？是否需要改动程序？keil或者IAR里，编译时，时钟，是否不填？
我已去掉了，但无法启动，基本上参考了这个文档，Clocking Options for Stellaris® Family Microcontrollers
Internal Oscillator
It is also possible to use the internal oscillator (or the internal oscillator divided by four) to clock the
device once the boot process has completed. The oscillator source is changed by modifying the
OSCSRC field of the RCC register in the System Control module.
A major hindrance to using the internal oscillator is that its accuracy is only guaranteed to be within
±50% of its ideal operating frequency of 15 MHz. Having such a large variance between devices
practically eliminates the usefulness of the internal oscillator as a clock source in a real-world
application. The primary use for the internal oscillator is for performing an internal clock check on the
main oscillator source.
Thisdriveriscontainedin driverlib/sysctl.c,with driverlib/sysctl.h containingthe
APIdefinitionsforusebyapplications.
还有DRL文档：Stellaris Peripheral Driver Library User's GuideP346页的API函数的说明 ，
改了sysctl。c程序的配置。
