TI中文支持网Part Number:TMS320F280025COther Parts Discussed in Thread:LAUNCHXL-F280025C, C2000WARE
SYSCLK配置的是100MHz，在On-Chip界面显示CPUCLK为95MHz
二者频率为什么不一样？
Yale Li：
它们之间的关系可以看一下spruin7b_TMS320F28002x Real-Time Microcontrollers Technical Reference Manual (Rev. B)第96页3.7 Clocking：
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BabaXibo：
谢谢
那这个CPUCLK如何配置？
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Yale Li：
PLLSYSCLK、SYSCLK、CPUCLK是完全一样的。
截图使用的是哪个工程？
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BabaXibo：
截图是我自己搭建的工程，同样的我也使用了TI例程，发现也是cpuclk为95MHz，硬件为LAUNCHXL-F280025C开发板，
例程路径为c2000\C2000Ware_5_00_00_00\driverlib\f28002x\examples\led
截屏如下
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Yale Li：
我已经咨询了相关工程师：
https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1272655/tms320f280025c-cpuclk-in-on-chip-flash-debug-tools-setting
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Yale Li：
Since the frequency tolerance of the Internal oscillator is 10MHz +/-2% over full operating range and max device clock frequency is 100MHz, we have some risk of exceeding 100MHz if we choose 10x PLL multiplier with this clock source. Because of this we step back to give 95MHz nominal, and with variation of internal oscillator we will still not violate the 100MHz max.
CCS flash tool always uses internal oscillator since it is known frequency and eliminates need or risk of customer manually entering the value of their external clock(if they have one).
For external X-tal, with tighter tolerance, this is not a concern so we can set PLL to full 100MHz when that is the clock source.
