[XMC1300 EVM] - ADC 테스트
XMC1300은 저렴한 CORTEX-M0 코어를 가진 MCU임에도 아날로그 기능은 풍부하다. 두채널의 독립된 12비트 ADC모듈이 있고 각각 8채널 입력 가능하다. 특히 하드웨어적으로 FIR/IIR 필터가 존재 하는것이 특이하다.
XMC1300 ADC특징
- Two independent sample and hold stages with 8 analog input channels each
- Selectable result width of 8/10/12 bits
– Fast Compare Mode
– Independent result registers
– Configurable limit checking against programmable border values
– Data rate reduction through adding a selectable number of conversion results
– FIR/IIR filter with selectable coefficients
XMC1300 ADC 테스트 동영상
ADC5 에 연결되어 있는 가변저항의 전압값을 TFT LCD에 출력하는 예제
XMC1300 EVM ADC 핀맵
P2.0 -> VADC0.G0CH5
P2.6 -> VADC0.G0CH0
P2.7 -> VADC0.G0CH1
XMC1300 ADC초기화코드
void ADC_Init()
{
// Global ADC Initialization
WR_REG(VADC->CLC, VADC_CLC_DISR_Msk, VADC_CLC_DISR_Pos, 0);
// Wait till module clock is enabled
while((RD_REG(VADC->CLC, VADC_CLC_DISS_Msk, VADC_CLC_DISS_Pos))!= 0);
// Enable ORC; required due to erratum ADC_AI.003
WR_REG(COMPARATOR->ORCCTRL, COMPARATOR_ORCCTRL_ENORC0_Msk, COMPARATOR_ORCCTRL_ENORC0_Pos, 1);
// Initiate start up calibration
WR_REG(VADC->GLOBCFG, VADC_GLOBCFG_SUCAL_Msk, VADC_GLOBCFG_SUCAL_Pos, 1);
// Enable wait-for-read mode
WR_REG(VADC_G0->RCR[0], VADC_G_RCR_WFR_Msk, VADC_G_RCR_WFR_Pos, 1);
// Configure Scan source
// Select G1CH7 on P2.5 as input channel
WR_REG(VADC_G0->ASSEL, VADC_G_ASSEL_CHSEL5_Msk, VADC_G_ASSEL_CHSEL5_Pos, 1);
WR_REG(VADC_G0->ASMR, VADC_G_ASMR_ENGT_Msk, VADC_G_ASMR_ENGT_Pos, 1); //Enable gate
WR_REG(VADC_G0->ASMR, VADC_G_ASMR_SCAN_Msk, VADC_G_ASMR_SCAN_Pos, 1); //Enable autoscan
WR_REG(VADC_G0->ASMR, VADC_G_ASMR_LDEV_Msk, VADC_G_ASMR_LDEV_Pos, 1); //Generate a load event
// Arbitration
// Select normal operation
WR_REG(VADC_G0->ARBCFG, VADC_G_ARBCFG_ANONC_Msk, VADC_G_ARBCFG_ANONC_Pos, 3);
// Enable arbitration slot 1
WR_REG(VADC_G0->ARBPR, VADC_G_ARBPR_ASEN1_Msk, VADC_G_ARBPR_ASEN1_Pos, 1);
// Wait till calibration is completed
while((RD_REG(VADC_G0->ARBCFG, VADC_G_ARBCFG_CAL_Msk, VADC_G_ARBCFG_CAL_Pos))!= 0);
}
XMC1300 ADC Read 함수
adc_result = VADC_G0->RES[0];
// Check if new conversion result is available
if (adc_result & VADC_G_RES_VF_Msk)
{
adc_result &= VADC_G_RES_RESULT_Msk;
adc_result = (adc_result >> 2);
DebugPrint("%d\r\n", adc_result);
}
