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LPC54628: Update the ADC clock divider based on the input clock source #7201

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merged 1 commit into from Jun 18, 2018
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LPC54628: Update the ADC clock divider based on the input clock source #7201

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22 changes: 16 additions & 6 deletions targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_LPC/analogin_api.c
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Expand Up @@ -30,9 +30,13 @@ static ADC_Type *const adc_addrs[] = ADC_BASE_PTRS;
extern void ADC_ClockPower_Configuration(void);

#define MAX_FADC 6000000
#define MAX_ADC_CLOCK 80000000

void analogin_init(analogin_t *obj, PinName pin)
{
uint32_t clkval;
uint32_t clkdiv = 1;

obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
MBED_ASSERT(obj->adc != (ADCName)NC);

Expand All @@ -42,23 +46,29 @@ void analogin_init(analogin_t *obj, PinName pin)
uint32_t pin_number = pin & 0x1F;
uint8_t port_number = pin / 32;

/* Clear the DIGIMODE bit */
reg = IOCON->PIO[port_number][pin_number] & ~IOCON_PIO_DIGIMODE_MASK;
IOCON->PIO[port_number][pin_number] = reg;

ADC_ClockPower_Configuration();

/* Ensure the ADC clock derived from the system clock is less than 80MHz */
clkval = CLOCK_GetFreq(kCLOCK_CoreSysClk);
while ((clkval / clkdiv) > MAX_ADC_CLOCK) {
clkdiv++;
}

/* Calibration after power up. */
if (!(ADC_DoSelfCalibration(adc_addrs[instance]))) {
/* Calibration failed */
return;
}

ADC_GetDefaultConfig(&adc_config);
adc_config.clockDividerNumber = 1;
adc_config.clockDividerNumber = clkdiv;

ADC_Init(adc_addrs[instance], &adc_config);
pinmap_pinout(pin, PinMap_ADC);

/* Clear the DIGIMODE bit */
reg = IOCON->PIO[port_number][pin_number] & ~IOCON_PIO_DIGIMODE_MASK;
IOCON->PIO[port_number][pin_number] = reg;
}

uint16_t analogin_read_u16(analogin_t *obj)
Expand All @@ -70,7 +80,7 @@ uint16_t analogin_read_u16(analogin_t *obj)

adcConvSeqConfigStruct.channelMask = (1U << channel);
adcConvSeqConfigStruct.triggerMask = 0U;
adcConvSeqConfigStruct.triggerPolarity = kADC_TriggerPolarityNegativeEdge;
adcConvSeqConfigStruct.triggerPolarity = kADC_TriggerPolarityPositiveEdge;
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Any partricular reason why this polarity flip was needed?

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This is to match the values set inside the MCUXpresso SDK examples.

adcConvSeqConfigStruct.enableSingleStep = false;
adcConvSeqConfigStruct.enableSyncBypass = false;
adcConvSeqConfigStruct.interruptMode = kADC_InterruptForEachSequence;
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