旋转编码器软解码
英飞凌AURIX系列支持RDC软解码。如上图所示，主要使用PWMP和PWMN两路信号软件方式产生一对正弦激励信号（10K）,旋变产生的SIN和COS信号返回给DSADC通道做软解码使用。
软解码初始化函数
void DSADC_RDC_Init(void)
{
DSADC_ModuleInit();
DSADC_RDC_ChannelInit();
DSADC_GLOBRC.U = 0x30003;//restart CH0 conversion
}
初始化模块
void DSADC_ModuleInit(void)
{
// create module config
IfxDsadc_Dsadc_Config dsadcConfig;
IfxDsadc_Dsadc_initModuleConfig(&dsadcConfig, &MODULE_DSADC);
// initialize module
IfxDsadc_Dsadc_initModule(&dsadc, &dsadcConfig);
}
RDC硬件配置
void DSADC_RDC_ChannelInit(void)
{
boolean result = TRUE;
IfxDsadc_Rdc_Config config;
IfxDsadc_Rdc_ConfigHw ConfigHw;
IfxDsadc_Dsadc_CarrierGenConfig configCarrier;
IfxDsadc_Dsadc_ChannelConfig configChannel;
/* FIXME add initConfig() */
int signDelay = 1; /* APPLICATION SPECIFIC */
/** Carrier generation configuration */
configCarrier.bitReversed = TRUE; /* Default */
configCarrier.carrierWaveformMode = IfxDsadc_CarrierWaveformMode_sine; /* Default */
configCarrier.frequency = 10e3; /* Default. This is only the expected frequency, real frequency may differ */
configCarrier.inverted = FALSE; /* Default */
configCarrier.pinDriver = IfxPort_PadDriver_cmosAutomotiveSpeed1; /* Default. recommended, but it can be also board specific. */
configCarrier.pinMode = IfxPort_OutputMode_pushPull; /* Default. recommended, but it can be also board specific. */
configCarrier.pinNeg = &IfxDsadc_CGPWMN_P33_11_OUT; /* APPLICATION SPECIFIC */
configCarrier.pinPos = &IfxDsadc_CGPWMP_P33_12_OUT; /* APPLICATION SPECIFIC */
/** Default configuration for one DSADC resolver input channel */
configChannel.auxFilter.bypassed = TRUE; /* Default. Don't change */
configChannel.auxFilter.combFilterShift = IfxDsadc_AuxCombFilterShift_noShift; /* Don't care, unused */
configChannel.auxFilter.combFilterType = IfxDsadc_AuxCombFilterType_comb1; /* Don't care, unused */
configChannel.auxFilter.decimationFactor = 4; /* Don't care, unused */
configChannel.auxFilter.eventGate = IfxDsadc_AuxGate_definedByESEL; /* Don't care, unused */
configChannel.auxFilter.eventSelect = IfxDsadc_AuxEvent_everyNewResult; /* Don't care, unused */
configChannel.auxFilter.serviceRequest = IfxDsadc_AuxServiceRequest_never; /* Default. Don't change */
configChannel.channelId = 0; /* Don't care, will be overwritten by driver */
configChannel.channelPins = NULL_PTR; /* Don't care, will be overwritten by driver */
configChannel.combFilter.bypassed = FALSE; /* Default. Don't change */
configChannel.combFilter.combFilterShift = IfxDsadc_MainCombFilterShift_shiftBy3; /* APPLICATION SPECIFIC */
configChannel.combFilter.combFilterType = IfxDsadc_MainCombFilterType_comb3; /* APPLICATION SPECIFIC */
configChannel.combFilter.decimationFactor = 16; /* APPLICATION SPECIFIC */
configChannel.combFilter.serviceRequest = IfxDsadc_MainServiceRequest_everyNewResult; /* Default. Don't change */
configChannel.combFilter.startValue = 1; /* Default. Don't change */
configChannel.demodulator.inputDataSource = IfxDsadc_InputDataSource_onChipStandAlone; /* Default. Don't change */
configChannel.demodulator.integrationTrigger = IfxDsadc_IntegratorTrigger_alwaysActive; /* Default. Don't change */
configChannel.demodulator.sampleClockSource = IfxDsadc_SampleClockSource_internal; /* Default. Don't change */
configChannel.demodulator.sampleStrobe = IfxDsadc_SampleStrobe_sampleOnRisingEdge; /* Default. Don't change */
configChannel.demodulator.timestampTrigger = (INVERTER_TRIGGER_RISING_EDGE_AT_PERIOD
? IfxDsadc_TimestampTrigger_fallingEdge
: IfxDsadc_TimestampTrigger_risingEdge);
configChannel.demodulator.triggerInput = IfxDsadc_TriggerInput_a; /* APPLICATION SPECIFIC */
configChannel.firFilter.dataShift = IfxDsadc_FirDataShift_shiftBy2; /* APPLICATION SPECIFIC */
configChannel.firFilter.fir0Enabled = TRUE; /* APPLICATION SPECIFIC */
configChannel.firFilter.fir1Enabled = TRUE; /* APPLICATION SPECIFIC */
configChannel.firFilter.internalShift = IfxDsadc_FirInternalShift_noShift; /* APPLICATION SPECIFIC */
configChannel.firFilter.offsetCompensation = TRUE; /* Default. Don't change */
configChannel.integrator.discardCount = signDelay + 1; /* Default */
configChannel.integrator.integrationCount = 16; /* Default */
configChannel.integrator.integrationCycles = 1; /* Default. Don't change */
configChannel.integrator.windowSize = IfxDsadc_IntegrationWindowSize_internalControl;/* Default. Don't change */
configChannel.modulator.commonModeVoltage = IfxDsadc_CommonModeVoltage_b; /* Default */
configChannel.modulator.inputGain = IfxDsadc_InputGain_factor1; /* Default */
configChannel.modulator.inputPin = IfxDsadc_InputPin_a; /* Don't care, will be overwritten by driver */
configChannel.modulator.modulatorClockFreq = 10.0e6; /* Default. This is only the expected frequency, real frequency may differ */
configChannel.modulator.negativeInput = IfxDsadc_InputConfig_inputPin; /* Default. Don't change */
configChannel.modulator.positiveInput = IfxDsadc_InputConfig_inputPin; /* Default. Don't change */
configChannel.module = &MODULE_DSADC; /* Default */
configChannel.rectifier.enabled = TRUE; /* Default. Don't change */
configChannel.rectifier.signDelay = signDelay; /* Default */
configChannel.rectifier.signPeriod = 16; /* Default */
configChannel.rectifier.signSource = IfxDsadc_RectifierSignSource_onChipGenerator;/* Default */
/** Hardware configuration for DSADC resolver interface */
ConfigHw.carrierGen = configCarrier;
/* Here DSADC event is connected into a TIM channel. In this example, TIM0 CH0 is used.
* Then, from tc27xC_um_v2.0OM.pdf Table 26-72 or Table 26-73, MUX value of b1011 is obtained */
ConfigHw.gtmTimestamp.gtm = &MODULE_GTM;
/* IfxGtm_ATOM0_7_TOUT7_P02_7 can be connected to TIM1 CH7 with mux. value b0001 */
ConfigHw.gtmTimestamp.pwmTim = &IfxGtm_TIM1_7_TIN7_P02_7_IN;
ConfigHw.gtmTimestamp.rdcTim = IfxGtm_Tim_1;
ConfigHw.gtmTimestamp.rdcTimChannel = IfxGtm_Tim_Ch_0;
ConfigHw.gtmTimestamp.rdcTimMuxValue = 11;
ConfigHw.inputConfig = configChannel;
ConfigHw.inputSin = IfxDsadc_ChannelId_1;
ConfigHw.inputCos = IfxDsadc_ChannelId_0;
ConfigHw.outputClock = NULL_PTR;
ConfigHw.servReqPriority = IFX_INTPRIO_DSADC_CH0_PRIO;
ConfigHw.servReqProvider = 0;
ConfigHw.startScan = FALSE;
/** Configuration for DSADC resolver interface */
/* set ALL gain to zero for using default values */
config.kd = 0;
config.ki = 0;
config.kp = 0;
config.errorThreshold = 1.0f / 180 * IFX_PI; /* Default */
config.hardware = ConfigHw;
config.offset = 0; /* APPLICATION SPECIFIC */
config.periodPerRotation = 3; /* APPLICATION SPECIFIC */
config.resolution = 4096; /* APPLICATION SPECIFIC */
config.reversed = 0; /* APPLICATION SPECIFIC */
config.speedLpfFc = 35;//30~100 /* Default */
config.sqrAmplMax = 3500*3500;//2700*2700 /* APPLICATION SPECIFIC */
config.sqrAmplMin = 1000*1000;//2100*2100 /* APPLICATION SPECIFIC */
config.userTs = 0.0001; /* Default */
config.dsadc = &dsadc; /* Default */
result &= IfxDsadc_Rdc_init(&Rdc, &config);
result &= IfxDsadc_Rdc_stdIfPosInit(&dsadcRdc, &Rdc);
}