CCS/MSP430FR6047: DSP LEA command

Hello LEA expert:

software-dl.ti.com/.../structMSP__LEA__POLY__PARAMS.html

The above URL is where the command is located.

Hello Srinivas Lingam,

The coeff is defined as a uint16_t, not an array.

How can I convert [P0 P1 P2 P3 P4] to a uint16_t.

Hello,

It is cast internally as a uint16_t*.

You will notice the same with the declaration for the output. Even though it is declared as uint16_t, it is internally used as a uint16_t*. I think it is cast internally inside the DSPLIB accordingly. You can see similar declaration with all the other functions.

Srinivas

Hello Srinivas Lingam,

On FR6047, I modify the contents of matrix_ex1_add_q15.c in DSPLib_1_30_00_02\examples\Matrix as follows

Why the content of result is 20005 instead of 28693?

I don't know what's wrong with my code. Please help me, thank you!

// p₄ = 20004 * 2^-15 = 0.610473633

// p₃ = 20003 * 2^-15 = 0.610443115

// p₂ = 20002 * 2^-15 = 0.610412598

// p₁ = 20001 * 2^-15 = 0.61038208

// p₀ = 20000 * 2^-15 = 0.610351563

// scaleFactor = 20006 * 2^-15 = 0.610534668

// order = 4

// x = 20005* 2^-15 = 0.61050415

/* Input x */
DSPLIB_DATA(inputA,4)
_q15 inputA;

/* Input coeff */
DSPLIB_DATA(inputB,4)
_q15 inputB[5];

/* Result y */
DSPLIB_DATA(result,4)
_q15 result;

void polynomial_q15(const _q15 *srcA, const _q15 *srcB, _q15 *dst)
{
    MSP_LEA_POLY_PARAMS *leaParams;

    /* Initialize LEA if it is not enabled. */
    if (!(LEAPMCTL & LEACMDEN)) {
        msp_lea_init();
    }
        
    /* Allocate MSP_LEA_POLY_PARAMS structure. */
    leaParams = (MSP_LEA_POLY_PARAMS *)msp_lea_allocMemory(sizeof(MSP_LEA_POLY_PARAMS)/sizeof(uint32_t));

    /* Set MSP_LEA_POLY_PARAMS structure. */
    
    
    leaParams->output = MSP_LEA_CONVERT_ADDRESS(dst);
    leaParams->coeff = MSP_LEA_CONVERT_ADDRESS(srcB);
    leaParams->order = 4;
    leaParams->scaleFactor = 20006; // 20006 * 2^-15

    /* Load source arguments to LEA. */
    LEAPMS0 = MSP_LEA_CONVERT_ADDRESS(srcA);
    LEAPMS1 = MSP_LEA_CONVERT_ADDRESS(leaParams);

    /* Invoke the LEACMD__POLYNOMIAL command. */
    msp_lea_invokeCommand(LEACMD__POLYNOMIAL);

    /* Free MSP_LEA_POLY_PARAMS structure. */
    msp_lea_freeMemory(sizeof(MSP_LEA_POLY_PARAMS)/sizeof(uint32_t));

    /* Free lock for LEA module and return status. */
    msp_lea_freeLock();
    return;
}

void main(void)
{
    /* Disable WDT. */
    WDTCTL = WDTPW + WDTHOLD;

#ifdef __MSP430_HAS_PMM__
    /* Disable GPIO power-on default high-impedance mode for FRAM devices */
    PM5CTL0 &= ~LOCKLPM5;
#endif

    inputA = 20005; // 20005 * 2^-15
    inputB[0] = 20000; // 20000 * 2^-15
    inputB[1] = 20001; // 20001 * 2^-15
    inputB[2] = 20002; // 20002 * 2^-15
    inputB[3] = 20003; // 20003 * 2^-15
    inputB[4] = 20004; // 20004 * 2^-15
    polynomial_q15(&inputA, inputB, &result);
    
    /* End of program. */
    __no_operation();
}

Hello Srinivas Lingam,

On FR6047, I didn't get the right result.