3.3.2 Using the Library

The EMAFE peripheral library can be used in different ways:

Direct Transfer: Read data samples from the registers of the EMAFE peripheral.
DMA Transfer: Read a set of data samples from data memory.

Direct Transfer



APP_DATA appData;

/* Buffer setting */
#define APP_SAMPLE_CHANNELS                1600 // 320 samples/cycle(50Hz) * 5 cycles
/** Buffer to store sample sets */
static uint32_t pSamplesBuffer[APP_SAMPLE_CHANNELS] = {0};

void SYS_Initialize ( void* data )
{
    (...)
    
    EMAFE_Initialize();
    
    (...)
}

void _appEmafeCallback(uint32_t interruptStatus)
{
    if (interruptStatus & EMAFE_ISR_DRDY_Msk)
    {
        *appData.pSamplesData++ = EMAFE_GetDataChannel(EMAFE_CHN_2_ID);
        appData.samplesCounter++;

        if (appData.samplesCounter == APP_SAMPLE_CHANNELS)
        {
            EMAFE_DisableFilter(EMAFE_MR_LPF_ON2_Msk);
            EMAFE_DisableInterrupt(EMAFE_IDR_DRDY_Msk);
            appData.newDataReady = true;
        }
    }
}

static void _emafeADCReset(bool enable)
{
	if (enable) {
		/* Enable ADC SOFT RESET */
		EMAFE_ADCEnableSoftReset();
	} else {
		/* Disable ADC SOFT RESET */
		EMAFE_ADCDisableSoftReset();

		/* Wait SYSRDY */
		while (!(EMAFE_ADCIsAnalogSystemReady()));
	}
}

static void _emafeConfigADCChannels(bool tempEnable, uint8_t gainI1, uint8_t gainI2)
{
    /* EMAFE Release Reset */
	_emafeADCReset(false);
    
	/* Enable ADC Channels */
       EMAFE_ADCI0Enable(tempEnable);
	while (!EMAFE_ADCI0IsEnable());

	EMAFE_ADCI1Enable(gainI1);
	while (!EMAFE_ADCI1IsEnable());

	EMAFE_ADCV1Enable();
	while (!EMAFE_ADCV1IsEnable());

	EMAFE_ADCI2Enable(gainI2);
	while (!EMAFE_ADCI2IsEnable());

	EMAFE_ADCV2Enable();
	while (!EMAFE_ADCV2IsEnable());

	/* Set ADC clock configuration */
       EMAFE_ADCSetClockConfig(EMAFE_ADC_CLOCK_FREQRATIO_4,
			EMAFE_ADC_CLOCK_MCLKDIV_ANACK2);
}

void APP_Initialize ( void )
{
    /* Place the App state machine in its initial state. */
    appData.state = APP_STATE_ADC_CONTROL_INIT;
    
    appData.timer = SYS_TIME_HANDLE_INVALID;
    appData.pSamplesData = pSamplesBuffer;
    appData.samplesCounter = 0;
    appData.newDataReady = false;
    appData.dataFormat = EMAFE_EMR_FORMAT_FULLRANGE;
}

void APP_Tasks ( void )
{
    switch ( appData.state )
    {
        /* Application's initial state. */
        case APP_STATE_ADC_CONTROL_INIT:
        {
            _emafeConfigADCChannels(true, 0, 0);
            
            /* Enable Analog controls. First enable LDO. */
            appData.state = APP_STATE_ADC_ENABLE_LDO;
            SYS_TIME_DelayMS(1, &appData.timer);
            break;
        }

        case APP_STATE_ADC_ENABLE_LDO:
        {
            if ((appData.timer == SYS_TIME_HANDLE_INVALID) || (SYS_TIME_DelayIsComplete(appData.timer)))
            {
                if (EMAFE_ADCIsLDOEnable())
                {
                    appData.state = APP_STATE_ADC_ENABLE_BIAS;
                    appData.timer = SYS_TIME_HANDLE_INVALID;
                }
                else
                {
                    EMAFE_ADCEnableLDO();
                    SYS_TIME_DelayMS(10, &appData.timer);
                }
            }
        }
            break;

        case APP_STATE_ADC_ENABLE_BIAS:
        {
            if ((appData.timer == SYS_TIME_HANDLE_INVALID) || (SYS_TIME_DelayIsComplete(appData.timer)))
            {
                if (EMAFE_ADCIsBIASEnable())
                {
                    appData.state = APP_STATE_ADC_ENABLE_REF;
                    appData.timer = SYS_TIME_HANDLE_INVALID;
                }
                else
                {
                    EMAFE_ADCEnableBIAS();
                    SYS_TIME_DelayMS(10, &appData.timer);
                }
            }
        }
            break;

        case APP_STATE_ADC_ENABLE_REF:
        {
            if ((appData.timer == SYS_TIME_HANDLE_INVALID) || (SYS_TIME_DelayIsComplete(appData.timer)))
            {
                if (EMAFE_ADCIsREFEnable())
                {
                    appData.state = APP_STATE_FILTER_CONTROL_INIT;
                    appData.timer = SYS_TIME_HANDLE_INVALID;
                }
                else
                {
                    EMAFE_ADCEnableREF();
                    /* Wait 100 ms for VREF setting */
                    SYS_TIME_DelayMS(100, &appData.timer);
                }
            }
        }
            break;

        case APP_STATE_FILTER_CONTROL_INIT:
        {
            /* LPFIF reset */
            EMAFE_SoftReset();
            /* Decimation LPFIF Filters exits the reset state */
            EMAFE_SetSincDecimationFiltersReset(false);
            /* Set DSP clock prescaler ratio */
            EMAFE_SetClockPrescalerRatio(EMAFE_EMR_MCLKDIV_LPF_MCLKDIV4_Val);
            EMAFE_SetDataFormat(appData.dataFormat);
            EMAFE_SetOSR(EMAFE_EMR_OSR_OSR64_Val);
            
            appData.state = APP_STATE_FILTER_START_CAPTURE;
            SYS_TIME_DelayMS(2, &appData.timer);
            break;
        }

        case APP_STATE_FILTER_START_CAPTURE:
        {
            if (SYS_TIME_DelayIsComplete(appData.timer))
            {
                appData.newDataReady = false;
                appData.samplesCounter = 0;
                appData.pSamplesData = pSamplesBuffer;
                
                /* Register callback */
                EMAFE_CallbackRegister(_appEmafeCallback);
                
                /* Init Decimation Filters */
                EMAFE_EnableFilter(EMAFE_MR_LPF_ON2_Msk);
                
                /* Enable Interrupt */
                EMAFE_EnableInterrupt(EMAFE_IER_DRDY_Msk);
                
                appData.state = APP_STATE_FILTER_PRINT_SAMPLES;
            }
        }
            break;

        case APP_STATE_FILTER_PRINT_SAMPLES:
        {
            if (appData.newDataReady)
            {
                appData.pSamplesData = pSamplesBuffer;
                appData.samplesCounter = 0;
                appData.newDataReady = false;
                
                SYS_TIME_DelayMS(5, &appData.timer);
            }
            
            if (SYS_TIME_DelayIsComplete(appData.timer))
            {
                if (appData.samplesCounter < APP_SAMPLE_CHANNELS)
                {
                    uint16_t index;

                    for (index = 0; index < APP_SAMPLES_PRINT; index += 5)
                    {
                        uint32_t s0, s1, s2, s3, s4;

                        if (appData.dataFormat == EMAFE_EMR_FORMAT_FULLRANGE_Val)
                        {
                            s0 = *appData.pSamplesData;
                            appData.pSamplesData++;
                            s1 = *appData.pSamplesData;
                            appData.pSamplesData++;
                            s2 = *appData.pSamplesData;
                            appData.pSamplesData++;
                            s3 = *appData.pSamplesData;
                            appData.pSamplesData++;
                            s4 = *appData.pSamplesData;
                            appData.pSamplesData++;
                        } 
                        else 
                        {
                            s0 = *appData.pSamplesData << 8;
                            appData.pSamplesData++;
                            s1 = *appData.pSamplesData << 8;
                            appData.pSamplesData++;
                            s2 = *appData.pSamplesData << 8;
                            appData.pSamplesData++;
                            s3 = *appData.pSamplesData << 8;
                            appData.pSamplesData++;
                            s4 = *appData.pSamplesData << 8;
                            appData.pSamplesData++;
                        }

                        appData.samplesCounter += 5;

                        SYS_CONSOLE_Print(SYS_CONSOLE_INDEX_0, "%08X\r\n%08X\r\n%08X\r\n%08X\r\n%08X\r\n", 
                                      s0, s1, s2, s3, s4);
                    }

                    SYS_TIME_DelayMS(100, &appData.timer);
                }
                else
                {
                    appData.state = APP_STATE_FILTER_IDLE;
                }
            }
        }
            break;

        case APP_STATE_FILTER_IDLE:
        default:
        {
            /* TODO: Handle error in application's state machine. */
            break;
        }
    }
}

DMA Transfer



APP_DATA appData;

/* Buffer setting */
#define APP_SAMPLE_CHANNELS                1600 // 320 samples/cycle(50Hz) * 5 cycles
/** Buffer to store sample sets */
static uint32_t pSamplesBuffer[APP_SAMPLE_CHANNELS] = {0};

void SYS_Initialize ( void* data )
{
    (...)
    
    EMAFE_Initialize();
    
    (...)
}

void _appEmafeCallback(uint32_t interruptStatus)
{
    if (interruptStatus & EMAFE_IER_ENDRX_Msk)
    {
        EMAFE_DMATransfer(false, EMAFE_PTCR_RXTDIS_Msk);
        EMAFE_DisableInterrupt(EMAFE_IDR_ENDRX_Msk);
        appData.newDataReady = true;
    }
}

static void _emafeADCReset(bool enable)
{
	if (enable) {
		/* Enable ADC SOFT RESET */
		EMAFE_ADCEnableSoftReset();
	} else {
		/* Disable ADC SOFT RESET */
		EMAFE_ADCDisableSoftReset();

		/* Wait SYSRDY */
		while (!(EMAFE_ADCIsAnalogSystemReady()));
	}
}

static void _emafeConfigADCChannels(bool tempEnable, uint8_t gainI1, uint8_t gainI2)
{
    /* EMAFE Release Reset */
	_emafeADCReset(false);
    
	/* Enable ADC Channels */
       EMAFE_ADCI0Enable(tempEnable);
	while (!EMAFE_ADCI0IsEnable());

	EMAFE_ADCI1Enable(gainI1);
	while (!EMAFE_ADCI1IsEnable());

	EMAFE_ADCV1Enable();
	while (!EMAFE_ADCV1IsEnable());

	EMAFE_ADCI2Enable(gainI2);
	while (!EMAFE_ADCI2IsEnable());

	EMAFE_ADCV2Enable();
	while (!EMAFE_ADCV2IsEnable());

	/* Set ADC clock configuration */
       EMAFE_ADCSetClockConfig(EMAFE_ADC_CLOCK_FREQRATIO_4,
			EMAFE_ADC_CLOCK_MCLKDIV_ANACK2);
}

void APP_Initialize ( void )
{
    /* Place the App state machine in its initial state. */
    appData.state = APP_STATE_ADC_CONTROL_INIT;
    
    appData.timer = SYS_TIME_HANDLE_INVALID;
    appData.pSamplesData = pSamplesBuffer;
    appData.newDataReady = false;
    appData.dataFormat = EMAFE_EMR_FORMAT_FULLRANGE;
}

void APP_Tasks ( void )
{
    switch ( appData.state )
    {
        /* Application's initial state. */
        case APP_STATE_ADC_CONTROL_INIT:
        {
            _emafeConfigADCChannels(true, 0, 0);
            
            /* Enable Analog controls. First enable LDO. */
            appData.state = APP_STATE_ADC_ENABLE_LDO;
            SYS_TIME_DelayMS(1, &appData.timer);
            break;
        }

        case APP_STATE_ADC_ENABLE_LDO:
        {
            if ((appData.timer == SYS_TIME_HANDLE_INVALID) || (SYS_TIME_DelayIsComplete(appData.timer)))
            {
                if (EMAFE_ADCIsLDOEnable())
                {
                    appData.state = APP_STATE_ADC_ENABLE_BIAS;
                    appData.timer = SYS_TIME_HANDLE_INVALID;
                }
                else
                {
                    EMAFE_ADCEnableLDO();
                    SYS_TIME_DelayMS(10, &appData.timer);
                }
            }
        }
            break;

        case APP_STATE_ADC_ENABLE_BIAS:
        {
            if ((appData.timer == SYS_TIME_HANDLE_INVALID) || (SYS_TIME_DelayIsComplete(appData.timer)))
            {
                if (EMAFE_ADCIsBIASEnable())
                {
                    appData.state = APP_STATE_ADC_ENABLE_REF;
                    appData.timer = SYS_TIME_HANDLE_INVALID;
                }
                else
                {
                    EMAFE_ADCEnableBIAS();
                    SYS_TIME_DelayMS(10, &appData.timer);
                }
            }
        }
            break;

        case APP_STATE_ADC_ENABLE_REF:
        {
            if ((appData.timer == SYS_TIME_HANDLE_INVALID) || (SYS_TIME_DelayIsComplete(appData.timer)))
            {
                if (EMAFE_ADCIsREFEnable())
                {
                    appData.state = APP_STATE_FILTER_CONTROL_INIT;
                    appData.timer = SYS_TIME_HANDLE_INVALID;
                }
                else
                {
                    EMAFE_ADCEnableREF();
                    /* Wait 100 ms for VREF setting */
                    SYS_TIME_DelayMS(100, &appData.timer);
                }
            }
        }
            break;

        case APP_STATE_FILTER_CONTROL_INIT:
        {
            /* LPFIF reset */
            EMAFE_SoftReset();
            /* Decimation LPFIF Filters exits the reset state */
            EMAFE_SetSincDecimationFiltersReset(false);
            /* Set DSP clock prescaler ratio */
            EMAFE_SetClockPrescalerRatio(EMAFE_EMR_MCLKDIV_LPF_MCLKDIV4_Val);
            EMAFE_SetDataFormat(appData.dataFormat);
            EMAFE_SetOSR(EMAFE_EMR_OSR_OSR64_Val);
            
            appData.state = APP_STATE_FILTER_START_CAPTURE;
            SYS_TIME_DelayMS(2, &appData.timer);
            break;
        }

        case APP_STATE_FILTER_START_CAPTURE:
        {
            if (SYS_TIME_DelayIsComplete(appData.timer))
            {
                /* Register callback */
                EMAFE_CallbackRegister(_appEmafeCallback);
                
                /* Init Decimation Filters */
                EMAFE_EnableFilter(EMAFE_MR_LPF_ON2_Msk);
                
                /* Setup DMA */
                EMAFE_EnableDMAChannel(EMAFE_MR_DMACH2_Msk);
                
                EMAFE_DMATransfer(false, EMAFE_PTCR_RXTDIS_Msk);
                
                EMAFE_DMASetup(pSamplesBuffer, APP_SAMPLE_CHANNELS, NULL, 0);
                
                EMAFE_DMATransfer(true, EMAFE_PTCR_RXTEN_Msk);
                
                /* Enable Interrupt */
                EMAFE_EnableInterrupt(EMAFE_IER_ENDRX_Msk);
                
                appData.state = APP_STATE_FILTER_PRINT_SAMPLES;
            }
        }
            break;

        case APP_STATE_FILTER_PRINT_SAMPLES:
        {
            if (appData.newDataReady)
            {
                appData.newDataReady = false;
                appData.pSamplesData = pSamplesBuffer;
                appData.samplesCounter = 0;
                
                SYS_TIME_DelayMS(5, &appData.timer);
            }
            
            if (appData.pSamplesData != NULL)
            {
                if (SYS_TIME_DelayIsComplete(appData.timer))
                {
                    if (appData.samplesCounter < APP_SAMPLE_CHANNELS)
                    {
                        uint16_t index;
                        
                        for (index = 0; index < APP_SAMPLES_PRINT; index += 5)
                        {
                             uint32_t s0, s1, s2, s3, s4;

	                        if (appData.dataFormat == EMAFE_EMR_FORMAT_FULLRANGE_Val)
	                        {
	                            s0 = *appData.pSamplesData;
	                            appData.pSamplesData++;
	                            s1 = *appData.pSamplesData;
	                            appData.pSamplesData++;
	                            s2 = *appData.pSamplesData;
	                            appData.pSamplesData++;
	                            s3 = *appData.pSamplesData;
	                            appData.pSamplesData++;
	                            s4 = *appData.pSamplesData;
	                            appData.pSamplesData++;
	                        } 
	                        else 
	                        {
	                            s0 = *appData.pSamplesData << 8;
	                            appData.pSamplesData++;
	                            s1 = *appData.pSamplesData << 8;
	                            appData.pSamplesData++;
	                            s2 = *appData.pSamplesData << 8;
	                            appData.pSamplesData++;
	                            s3 = *appData.pSamplesData << 8;
	                            appData.pSamplesData++;
	                            s4 = *appData.pSamplesData << 8;
	                            appData.pSamplesData++;
	                        }

                               appData.samplesCounter += 5;

	                        SYS_CONSOLE_Print(SYS_CONSOLE_INDEX_0, "%08X\r\n%08X\r\n%08X\r\n%08X\r\n%08X\r\n", 
	                                      s0, s1, s2, s3, s4);
                    }

                        SYS_TIME_DelayMS(100, &appData.timer);
                    }
                    else
                    {
                        appData.pSamplesData = NULL;
                        appData.state = APP_STATE_FILTER_IDLE;
                    }
                }
            }
        }
            break;

        case APP_STATE_FILTER_IDLE:
        default:
        {
            /* TODO: Handle error in application's state machine. */
            break;
        }
    }
}