使用RT-thread studio 创建STM32F103工程后，将HSI改为HSE时的疑问求解

如下图，使用RT-thread studio 创建STM32F103工程后，准备将HSI 改为HSE 时，发现一个问题，

为什么F103 系列对应的RCC PLLMUL 是 16， 不应该是9吗？

#if defined(STM32F100xB) || defined(STM32F100xE)
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL6;
#endif
#if defined(STM32F101x6) || defined(STM32F101xB) || defined(STM32F101xE) || defined(STM32F101xG)
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
#endif
#if defined(STM32F102x6) || defined(STM32F102xB)
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
#endif
#if defined(STM32F103x6) || defined(STM32F103xB) || defined(STM32F103xE) || defined(STM32F103xG)
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;
#endif
#if defined(STM32F105xC) || defined(STM32F107xC)
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
#endif