7 应用代码

#define FILTER_ORDER 24
#define FIXED_POINT_PRECISION 16
volatile bool gCheckADC;
uint32_t gDelayLine[FILTER_ORDER];
uint32_t gResult = 0;
/* Filter coefficients are input as 16-bit Precision fixed point values  */

static int32_t filterCoeff[FILTER_ORDER] = {
  -62, -153, -56, 434, 969, 571,
  -1291, -3237, -2173, 3989, 13381, 20518,
  20518, 13381, 3989, -2173, -3237, -1291,
  571, 969, 434, -56, -153, -62
};

const DL_MathACL_operationConfig gMpyConfig = {
    .opType      = DL_MATHACL_OP_TYPE_MAC,
    .opSign      = DL_MATHACL_OPSIGN_SIGNED,
    .iterations  = 0,
    .scaleFactor = 0,
    .qType       = DL_MATHACL_Q_TYPE_Q16};

int main(void)
 {
    SYSCFG_DL_init();
    NVIC_EnableIRQ(ADC12_0_INST_INT_IRQN);
    gCheckADC = false;
    DL_ADC12_startConversion(ADC12_0_INST);

    /* Configure MathACL for Multiply */
    DL_MathACL_configOperation(MATHACL, &gMpyConfig, 0, 0 );

    while (1) {
        while (false == gCheckADC) {
            __WFE();
        }

        gCheckADC = false;
        gResult = 0;
        /* Append the most recent ADC result to the delay line */
        memmove(&gDelayLine[1], gDelayLine, sizeof(gDelayLine) - sizeof(gDelayLine[0]));
        gDelayLine[0] = DL_ADC12_getMemResult(ADC12_0_INST, DL_ADC12_MEM_IDX_0);

        /* Calculate FIR Filter Output */
        for (int i = 0; i < FILTER_ORDER; i++){
            /* Set Operand One last */
            DL_MathACL_setOperandTwo(MATHACL, filterCoeff[i]);
            DL_MathACL_setOperandOne(MATHACL, gDelayLine[i]);
            DL_MathACL_waitForOperation(MATHACL);
        }
        /* Our result should not exceed the bounds of RES1 register, in other applications you may use both RES1 and RES2 registers */
        gResult = DL_MathACL_getResultOne(MATHACL);
        DL_DAC12_output12(DAC0, (uint32_t)(gResult));
        
        /* Clear Results Registers */
        DL_MathACL_clearResults(MATHACL);
    }
}

/* Set the ADC Result flag to trigger our main loop to process the new data */
void ADC12_0_INST_IRQHandler(void)
{
    switch (DL_ADC12_getPendingInterrupt(ADC12_0_INST)) {
        case DL_ADC12_IIDX_MEM0_RESULT_LOADED:
            gCheckADC = true;
            break;
        default:
            break;
    }
}