Hi, It is OK like this: RCCU_Div2Config(ENABLE); RCCU_MCLKConfig(RCCU_DEFAULT); RCCU_FCLKConfig(RCCU_RCLK_8); RCCU_PCLKConfig(RCCU_RCLK_8); RCCU_PLL1Config(RCCU_PLL1_Mul_12 , RCCU_Div_4) ; while(RCCU_FlagStatus(RCCU_PLL1_LOCK) == RESET); RCCU_RCLKSourceConfig(RCCU_PLL1_Output) ; when i change RCCU_PLL1Config(RCCU_PLL1_Mul_12 , RCCU_Div_4) ; to RCCU_PLL1Config(RCCU_PLL1_Mul_12 , RCCU_Div_2) ; code can't run. so,MCLKval=24M is OK MCLKval=48M is failure. Is it a hardware problem? MCLKval=RCCU_FrequencyValue (RCCU_MCLK); APB1CLKval=RCCU_FrequencyValue (RCCU_FCLK); APB2CLKval=RCCU_FrequencyValue (RCCU_PCLK); thank you in advance.
What clock are you driving the str7 with ? Here ia an example of using a 16MHz clock input RCCU_Div2Config( ENABLE ); RCCU_MCLKConfig( RCCU_DEFAULT ); RCCU_FCLKConfig( RCCU_RCLK_2 ); RCCU_PCLKConfig( RCCU_RCLK_2 ); RCCU_PLL1Config( RCCU_PLL1_Mul_12, RCCU_Div_2 ); RCCU_RCLKSourceConfig( RCCU_PLL1_Output ); This will give us a MCLK of 48MHz and a peripheral clock of 24MHz I have noticed that when debugging the clocks can sometimes get locked up. If you have get this behaviour then insert the follwing before the clock config above. This will reset the clock to the default state before changing to the new clcok source. RCCU_RCLKSourceConfig( RCCU_CLOCK2 ); Hope this helps. Spen
Guest
#1171892
Spen: yes, i am using a 16MHz clock input. so I think it is something wrong with hardware. thank you very much indeed.
Guest
#1171893
Spencer Oliver wrote: > > I have noticed that when debugging the clocks can sometimes get locked > up. > If you have get this behaviour then insert the follwing before the clock > config above. This will reset the clock to the default state before > changing to the new clcok source. > RCCU_RCLKSourceConfig( RCCU_CLOCK2 ); > I try this today. You are right. add RCCU_RCLKSourceConfig( RCCU_CLOCK2 ); before the clock config,my board can run at 48M. Thank you very much indeed.
Note this should only need doing for debugging, when the device is reset from cold then the RCCU_CLOCK2 option is enabled by default. Some ide's use a reset script that perform similar behaviour to adding this line. Regards Spen