【GD32F350开发分享二】GD32F350时钟配置，非常重要

Justice_Gao

【GD32F350开发分享二】GD32F350时钟配置，非常重要 [复制链接]

大家应该都知道，微控制器最重要的就是时钟频率，时钟频率会影响指令周期、定时器、RTC等等所有涉及时钟的总线。
GD32F350开发板的外部高速时钟8MHZ晶振和外部低速时钟32.768KHZ晶振没有焊接，大家有需要自行焊接。
我用的是内部时钟8MHZ，当然，如果需要用时钟频率进行定时器中断设置的，建议使用外部晶振，因为外部晶振精度高，偏移量小，但是缺点在于功耗就大了，内部时钟功耗低，但是精度会差一些；
以下是我的时钟配置

1. 
   
2. /* system frequency define */
   
3. #define __IRC8M           (IRC8M_VALUE)            /* internal 8 MHz RC oscillator frequency */
   
4. #define __HXTAL           (HXTAL_VALUE)            /* high speed crystal oscillator frequency */
   
5. #define __SYS_OSC_CLK     (__IRC8M)                /* main oscillator frequency */
   
6. 
   
7. /* select a system clock by uncommenting the following line */
   
8. #if defined (GD32F330)
   
9. //#define __SYSTEM_CLOCK_8M_HXTAL              (__HXTAL)
   
10. //#define __SYSTEM_CLOCK_8M_IRC8M              (__IRC8M)
    
11. //#define __SYSTEM_CLOCK_72M_PLL_HXTAL         (uint32_t)(72000000)
    
12. //#define __SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2    (uint32_t)(72000000)
    
13. //#define __SYSTEM_CLOCK_72M_PLL_IRC48M_DIV2     (uint32_t)(72000000)
    
14. #define __SYSTEM_CLOCK_84M_PLL_HXTAL           (uint32_t)(84000000)
    
15. //#define __SYSTEM_CLOCK_84M_PLL_IRC8M_DIV2    (uint32_t)(84000000)
    
16. #endif /* GD32F330 */
    
17. 
    
18. #if defined (GD32F350)
    
19. //#define __SYSTEM_CLOCK_8M_HXTAL              (__HXTAL)
    
20. #define __SYSTEM_CLOCK_8M_IRC8M              (__IRC8M)
    
21. //#define __SYSTEM_CLOCK_72M_PLL_HXTAL         (uint32_t)(72000000)
    
22. //#define __SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2    (uint32_t)(72000000)
    
23. //#define __SYSTEM_CLOCK_84M_PLL_HXTAL         (uint32_t)(84000000)
    
24. //#define __SYSTEM_CLOCK_84M_PLL_IRC8M_DIV2    (uint32_t)(84000000)
    
25. //#define __SYSTEM_CLOCK_96M_PLL_HXTAL         (uint32_t)(96000000)
    
26. //#define __SYSTEM_CLOCK_96M_PLL_IRC8M_DIV2      (uint32_t)(96000000)
    
27. //#define __SYSTEM_CLOCK_96M_PLL_IRC48M_DIV2     (uint32_t)(96000000)
    
28. //#define __SYSTEM_CLOCK_108M_PLL_HXTAL        (uint32_t)(108000000)
    
29. //#define __SYSTEM_CLOCK_108M_PLL_IRC8M_DIV2   (uint32_t)(108000000)
    
30. #endif /* GD32F350 */
    
31. 
    
32. #define SEL_IRC8M       0x00
    
33. #define SEL_HXTAL       0x01
    
34. #define SEL_PLL         0x02
    
35. 
    
36. /* set the system clock frequency and declare the system clock configuration function */
    
37. #ifdef __SYSTEM_CLOCK_8M_HXTAL
    
38. uint32_t SystemCoreClock = __SYSTEM_CLOCK_8M_HXTAL;
    
39. static void system_clock_8m_hxtal(void);
    
40. 
    
41. #elif defined (__SYSTEM_CLOCK_72M_PLL_HXTAL)
    
42. uint32_t SystemCoreClock = __SYSTEM_CLOCK_72M_PLL_HXTAL;
    
43. static void system_clock_72m_hxtal(void);
    
44. 
    
45. #elif defined (__SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2)
    
46. uint32_t SystemCoreClock = __SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2;
    
47. static void system_clock_72m_irc8m(void);
    
48. 
    
49. #elif defined (__SYSTEM_CLOCK_72M_PLL_IRC48M_DIV2)
    
50. uint32_t SystemCoreClock = __SYSTEM_CLOCK_72M_PLL_IRC48M_DIV2;
    
51. static void system_clock_72m_irc48m(void);
    
52. 
    
53. #elif defined (__SYSTEM_CLOCK_84M_PLL_HXTAL)
    
54. uint32_t SystemCoreClock = __SYSTEM_CLOCK_84M_PLL_HXTAL;
    
55. static void system_clock_84m_hxtal(void);
    
56. 
    
57. #elif defined (__SYSTEM_CLOCK_84M_PLL_IRC8M_DIV2)
    
58. uint32_t SystemCoreClock = __SYSTEM_CLOCK_84M_PLL_IRC8M_DIV2;
    
59. static void system_clock_84m_irc8m(void);
    
60. 
    
61. #elif defined (__SYSTEM_CLOCK_96M_PLL_HXTAL)
    
62. uint32_t SystemCoreClock = __SYSTEM_CLOCK_96M_PLL_HXTAL;
    
63. static void system_clock_96m_hxtal(void);
    
64. 
    
65. #elif defined (__SYSTEM_CLOCK_96M_PLL_IRC8M_DIV2)
    
66. uint32_t SystemCoreClock = __SYSTEM_CLOCK_96M_PLL_IRC8M_DIV2;
    
67. static void system_clock_96m_irc8m(void);
    
68. 
    
69. #elif defined (__SYSTEM_CLOCK_96M_PLL_IRC48M_DIV2)
    
70. uint32_t SystemCoreClock = __SYSTEM_CLOCK_96M_PLL_IRC48M_DIV2;
    
71. static void system_clock_96m_irc48m(void);
    
72. 
    
73. #elif defined (__SYSTEM_CLOCK_108M_PLL_HXTAL)
    
74. uint32_t SystemCoreClock = __SYSTEM_CLOCK_108M_PLL_HXTAL;
    
75. static void system_clock_108m_hxtal(void);
    
76. 
    
77. #elif defined (__SYSTEM_CLOCK_108M_PLL_IRC8M_DIV2)
    
78. uint32_t SystemCoreClock = __SYSTEM_CLOCK_108M_PLL_IRC8M_DIV2;
    
79. static void system_clock_108m_irc8m(void);
    
80. 
    
81. #else
    
82. uint32_t SystemCoreClock = __SYSTEM_CLOCK_8M_IRC8M;
    
83. static void system_clock_8m_irc8m(void);
    
84. #endif /* __SYSTEM_CLOCK_8M_HXTAL */
    
85. 
    
86. /* configure the system clock */
    
87. static void system_clock_config(void);
    
88. 
    
89. /*!
    
90.     \brief      setup the microcontroller system, initialize the system
    
91.     \param[in]  none
    
92.     \param[out] none
    
93.     \retval     none
    
94. */
    
95. void SystemInit (void)
    
96. {
    
97.     /* enable IRC8M */
    
98.     RCU_CTL0 |= RCU_CTL0_IRC8MEN;
    
99.     while(0U == (RCU_CTL0 & RCU_CTL0_IRC8MSTB)){
    
100.     }
     
101.     /* reset RCU */
     
102.     RCU_CFG0 &= ~(RCU_CFG0_SCS | RCU_CFG0_AHBPSC | RCU_CFG0_APB1PSC | RCU_CFG0_APB2PSC |\
     
103.                   RCU_CFG0_ADCPSC | RCU_CFG0_CKOUTSEL | RCU_CFG0_CKOUTDIV | RCU_CFG0_PLLDV);
     
104.     RCU_CFG0 &= ~(RCU_CFG0_PLLSEL | RCU_CFG0_PLLMF | RCU_CFG0_PLLMF4 | RCU_CFG0_PLLDV);
     
105. #if (defined(GD32F350))
     
106.     RCU_CFG0 &= ~(RCU_CFG0_USBFSPSC);
     
107.     RCU_CFG2 &= ~(RCU_CFG2_CECSEL | RCU_CFG2_USBFSPSC2);
     
108. #endif /* GD32F350 */
     
109.     RCU_CTL0 &= ~(RCU_CTL0_HXTALEN | RCU_CTL0_CKMEN | RCU_CTL0_PLLEN | RCU_CTL0_HXTALBPS);
     
110.     RCU_CFG1 &= ~(RCU_CFG1_PREDV | RCU_CFG1_PLLMF5 | RCU_CFG1_PLLPRESEL);
     
111.     RCU_CFG2 &= ~(RCU_CFG2_USART0SEL | RCU_CFG2_ADCSEL);
     
112.     RCU_CFG2 &= ~RCU_CFG2_IRC28MDIV;
     
113.     RCU_CFG2 &= ~RCU_CFG2_ADCPSC2;
     
114.     RCU_CTL1 &= ~RCU_CTL1_IRC28MEN;
     
115.     RCU_ADDCTL &= ~RCU_ADDCTL_IRC48MEN;
     
116.     RCU_INT = 0x00000000U;
     
117.     RCU_ADDINT = 0x00000000U;
     
118.     /* configure system clock */
     
119.     system_clock_config();
     
120. }
     
121. 
     
122. /*!
     
123.     \brief      configure the system clock
     
124.     \param[in]  none
     
125.     \param[out] none
     
126.     \retval     none
     
127. */
     
128. static void system_clock_config(void)
     
129. {
     
130. #ifdef __SYSTEM_CLOCK_8M_HXTAL
     
131.     system_clock_8m_hxtal();
     
132. #elif defined (__SYSTEM_CLOCK_72M_PLL_HXTAL)
     
133.     system_clock_72m_hxtal();
     
134. #elif defined (__SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2)
     
135.     system_clock_72m_irc8m();
     
136. #elif defined (__SYSTEM_CLOCK_72M_PLL_IRC48M_DIV2)
     
137.     system_clock_72m_irc48m();
     
138. #elif defined (__SYSTEM_CLOCK_84M_PLL_HXTAL)
     
139.     system_clock_84m_hxtal();
     
140. #elif defined (__SYSTEM_CLOCK_84M_PLL_IRC8M_DIV2)
     
141.     system_clock_84m_irc8m();
     
142. #elif defined (__SYSTEM_CLOCK_96M_PLL_HXTAL)
     
143.     system_clock_96m_hxtal();
     
144. #elif defined (__SYSTEM_CLOCK_96M_PLL_IRC8M_DIV2)
     
145.     system_clock_96m_irc8m();
     
146. #elif defined (__SYSTEM_CLOCK_96M_PLL_IRC48M_DIV2)
     
147.     system_clock_96m_irc48m();
     
148. #elif defined (__SYSTEM_CLOCK_108M_PLL_HXTAL)
     
149.     system_clock_108m_hxtal();
     
150. #elif defined (__SYSTEM_CLOCK_108M_PLL_IRC8M_DIV2)
     
151.     system_clock_108m_irc8m();
     
152. #else
     
153.     system_clock_8m_irc8m();
     
154. #endif /* __SYSTEM_CLOCK_8M_HXTAL */
     
155. }

复制代码

nmg

谢谢分享
眼熟，原来是参与过美信大赛，期待后续

Justice_Gao

nmg 发表于 2018-9-22 23:58
谢谢分享
眼熟，原来是参与过美信大赛，期待后续

哈哈 被你发现了