trng.c

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/**************************************************************************/
#include <stdio.h>

#include "NuMicro.h"


void TRNG_Open(void)
{
    SYS->IPRST1 |= SYS_IPRST1_TRNGRST_Msk;
    SYS->IPRST1 ^= SYS_IPRST1_TRNGRST_Msk;

    TRNG->CTL |= TRNG_CTL_TRNGEN_Msk;

    TRNG->ACT |= TRNG_ACT_ACT_Msk;

    /* Waiting for ready */
    while ((TRNG->CTL & TRNG_CTL_READY_Msk) == 0);
}


int32_t TRNG_GenWord(uint32_t *u32RndNum)
{
    uint32_t   i, u32Reg, timeout;

    *u32RndNum = 0;
    u32Reg = TRNG->CTL;

    for (i = 0; i < 4; i++)
    {
        TRNG->CTL = TRNG_CTL_TRNGEN_Msk | u32Reg;

        /* TRNG should generate one byte per 125*8 us */
        for (timeout = (CLK_GetHCLKFreq() / 100); timeout > 0; timeout--)
        {
            if (TRNG->CTL & TRNG_CTL_DVIF_Msk)
                break;
        }

        if (timeout == 0)
            return -1;

        *u32RndNum |= ((TRNG->DATA & 0xff) << i*8);

    }
    return 0;
}

int32_t TRNG_GenBignum(uint8_t u8BigNum[], int32_t i32Len)
{
    uint32_t   i, u32Reg, timeout;

    u32Reg = TRNG->CTL;

    for (i = 0; i < i32Len/8; i++)
    {
        TRNG->CTL = TRNG_CTL_TRNGEN_Msk | u32Reg;

        /* TRNG should generate one byte per 125*8 us */
        for (timeout = (CLK_GetHCLKFreq() / 100); timeout > 0; timeout--)
        {
            if (TRNG->CTL & TRNG_CTL_DVIF_Msk)
                break;
        }

        if (timeout == 0)
            return -1;

        u8BigNum[i] = (TRNG->DATA & 0xff);
    }
    return 0;
}

int32_t TRNG_GenBignumHex(char cBigNumHex[], int32_t i32Len)
{
    uint32_t   i, idx, u32Reg, timeout;
    uint32_t   data;

    u32Reg = TRNG->CTL;
    idx = 0;
    for (i = 0; i < i32Len/8; i++)
    {
        TRNG->CTL = TRNG_CTL_TRNGEN_Msk | u32Reg;

        /* TRNG should generate one byte per 125*8 us */
        for (timeout = (CLK_GetHCLKFreq() / 100); timeout > 0; timeout--)
        {
            if (TRNG->CTL & TRNG_CTL_DVIF_Msk)
                break;
        }

        if (timeout == 0)
            return -1;

        data = (TRNG->DATA & 0xff);

        if (data >= 0xA0)
            cBigNumHex[idx++] = ((data >> 4) & 0xf) - 10 + 'A';
        else
            cBigNumHex[idx++] = ((data >> 4) & 0xf) + '0';

        data &= 0xf;
        if (data >= 0xA)
            cBigNumHex[idx++] = data - 10 + 'A';
        else
            cBigNumHex[idx++] = data + '0';
    }
    cBigNumHex[idx] = 0;
    return 0;
}

 /* end of group TRNG_EXPORTED_FUNCTIONS */
 /* end of group TRNG_Driver */
 /* end of group Standard_Driver */

/*** (C) COPYRIGHT 2019 Nuvoton Technology Corp. ***/