Stm32 system clock configuration function

1. /*************************************** *************************************
2. *
3. * Name: rcc_configuration
4. *
5. * Description: sets the system clock.
6. *
7. * Return value: None
8. *
9. **************************************** ************************************/
10. Void rcc_configuration (void)
11. {
12. Errorstatus hsestartupstatus;
14. Rcc_deinit (); // RCC Reset
    
15. Rcc_hseconfig (rcc_hse_on); // enable external clock
    
16. Hsestartupstatus = rcc_waitforhsestartup (); // wait until the external clock is ready
    
18. If (hsestartupstatus = success)
19. {
20. Flash_prefetchbuffercmd (flash_prefetchbuffer_enable); // prefetch address cache enabling
    
21. Flash_setlatency (flash_latency_2); // two-period flash memory latency
    
22. Rcc_hclkconfig (rcc_sysclk_div1); // set the AHB clock to the system clock.
    
23. Rcc_pclk2config (rcc_hclk_div1); // set high-speed clock to AHB clock
    
24. Rcc_pclk1config (rcc_hclk_div2); // set the low-speed clock to AHB clock-2.
    
26. Rcc_pllconfig (rcc_pllsource_hse_div1, rcc_pllmul_9); // set the PLL to 72 m
    
27. Rcc_pllcmd (enable); // enable PLL
    
28. While (rcc_getflagstatus (rcc_flag_pllrdy) = reset) // wait for the PLL
    
29. {
30. }
31. Rcc_sysclkconfig (rcc_sysclksource_pllclk); // set the PLL to the system clock.
    
32. While (rcc_getsysclksource ()! = 0x08) // wait until the setting is complete
    
33. {
34. }
35. }
36. }