Hi…
i wnant to change ADC clock setting from standard ADC_CLOCK_MODE_ASYNCLK to ADC_CLOCK_MODE_SYNCLKDIV4…
but it seems “ADC_ClockMode” function has no effect and source clock is always 14mhz…
pl suggest,,,

  • 5
7 days later

Hi, so you want the source clock not to be internal HSI14, but div4 from PCLK? Did you also configure the ADC_EnableJitter() to fit div4? Did you switch the clock source when ADC is not activated?

Hi Chaos…

yes i want adc clock derived from pclk,,, i hv also enabled adc jitter,,, my source code is as in follows sequence,,,
SetSysClock();
GPIO_Init();
ADC_Init();

void SetSysClock() {
RCM_Reset();
RCM_ConfigSYSCLK(RCM_SYSCLK_SEL_HSI);
RCM_DisablePLL(); /* Disable PLL /
while (RCM->CTRL1_B.PLLRDYFLG == SET); / Wait until Pll is ready */

RCM_ConfigPLL(RCM_PLL_SEL_HSI_DIV2, RCM_PLLMF_8);
RCM_EnablePLL(); /* Enable PLL /
RCM_ConfigSYSCLK(RCM_SYSCLK_SEL_PLL); / Selct PLL as Sysclk */

RCM_ConfigAHB(RCM_SYSCLK_DIV_2);
RCM_ConfigAPB(RCM_HCLK_DIV_1);
FMC_SetLatency(FMC_LATENCY_1);

RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_SYSCFG);
RCM_EnableAHBPeriphClock(RCM_AHB_PERIPH_GPIOA);
RCM_EnableAHBPeriphClock(RCM_AHB_PERIPH_GPIOB);
RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_ADC1);
RCM_EnableAPB1PeriphClock(RCM_APB1_PERIPH_TMR3);
RCM_EnableAPB1PeriphClock(RCM_APB1_PERIPH_TMR14);
}

void GPIO_Init () {
GPIO_Config_T gpioConfig;
// configure pa1, pa2, pa3 pins as anlog input pins
gpioConfig.mode = GPIO_MODE_AN;
gpioConfig.pupd = GPIO_PUPD_NO;
gpioConfig.pin = GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3;
GPIO_Config(GPIOA, &gpioConfig);

// configure lcd port pins

gpioConfig.pin = D7_Pin | D6_Pin | D5_Pin | D4_Pin | EN_Pin;
gpioConfig.mode = GPIO_MODE_OUT;
gpioConfig.outtype = GPIO_OUT_TYPE_PP;
gpioConfig.speed = GPIO_SPEED_10MHz;
gpioConfig.pupd = GPIO_PUPD_PU;
GPIO_Config(GPIOB, &gpioConfig);

gpioConfig.pin = RW_Pin | RS_Pin ;
gpioConfig.mode = GPIO_MODE_OUT;
gpioConfig.outtype = GPIO_OUT_TYPE_PP;
gpioConfig.speed = GPIO_SPEED_10MHz;
gpioConfig.pupd = GPIO_PUPD_PU;
GPIO_Config(GPIOA, &gpioConfig);

// set all output pins to 0
GPIO_ClearBit(RW_GPIO_Port,RW_Pin);
GPIO_ClearBit(RS_GPIO_Port,RS_Pin);
GPIO_ClearBit(EN_GPIO_Port,EN_Pin);
GPIO_ClearBit(D7_GPIO_Port,D7_Pin);
GPIO_ClearBit(D6_GPIO_Port,D6_Pin);
GPIO_ClearBit(D5_GPIO_Port,D5_Pin);
GPIO_ClearBit(D4_GPIO_Port,D4_Pin);
}

void ADC_Init() {
ADC_Config_T adcConfig;

ADC_Reset();
   ADC_ClockMode(ADC_CLOCK_MODE_SYNCLKDIV4);
    ADC_EnableJitter(ADC_JITTER_PCLKDIV4);	

ADC_ConfigStructInit(&adcConfig);
adcConfig.resolution            = ADC_RESOLUTION_12B;
adcConfig.scanDir               = ADC_SCAN_DIR_UPWARD;
adcConfig.convMode              = ADC_CONVERSION_SINGLE;
adcConfig.dataAlign             = ADC_DATA_ALIGN_RIGHT;
adcConfig.extTrigConv           = ADC_EXT_TRIG_CONV_TRG0;
adcConfig.extTrigEdge           = ADC_EXT_TRIG_EDGE_NONE;

ADC_Config(&adcConfig);
ADC_ReadCalibrationFactor();	
ADC_Enable();
while (!ADC_ReadStatusFlag(ADC_FLAG_ADRDY)) {};

}

the output on lcd is as attached…

pl suggest how to modify clock to adc module…
thanks a lot…
John

a month later

ADC configuration register 2 (ADC_CFG2)
31:30 CLKCFG R/W
ADC Clock Mode Configure
00: ADCCLK (asynchronous clock mode)
01: PCLK/2 (synchronous clock mode)
10: PCLK/4 (synchronous clock mode)
11: Reserved
Note: The software allows writing these bits only when ADC is
disabled