i2s.c

Go to the documentation of this file.

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

static uint32_t I2S_GetSourceClockFreq(I2S_T *i2s);

static uint32_t I2S_GetSourceClockFreq(I2S_T *i2s)
{
    uint32_t u32Freq, u32ClkSrcSel;

    /* get I2S selection clock source */
    u32ClkSrcSel = CLK->CLKSEL3 & CLK_CLKSEL3_I2S0SEL_Msk;

    switch (u32ClkSrcSel)
    {
    case CLK_CLKSEL3_I2S0SEL_HXT:
        u32Freq = __HXT;
        break;

    case CLK_CLKSEL3_I2S0SEL_PLL:
        u32Freq = CLK_GetPLLClockFreq();
        break;

    case CLK_CLKSEL3_I2S0SEL_HIRC:
        u32Freq = __HIRC;
        break;

    case CLK_CLKSEL3_I2S0SEL_PCLK0:
        u32Freq = (uint32_t)CLK_GetPCLK0Freq();
        break;

    default:
        u32Freq = __HIRC;
        break;
    }

    return u32Freq;
}

uint32_t I2S_Open(I2S_T *i2s, uint32_t u32MasterSlave, uint32_t u32SampleRate, uint32_t u32WordWidth, uint32_t u32MonoData, uint32_t u32DataFormat)
{
    uint16_t u16Divider;
    uint32_t u32BitRate, u32SrcClk;

    SYS->IPRST1 |= SYS_IPRST1_I2S0RST_Msk;
    SYS->IPRST1 &= ~SYS_IPRST1_I2S0RST_Msk;

    i2s->CTL0 = u32MasterSlave | u32WordWidth | u32MonoData | u32DataFormat;
    i2s->CTL1 = I2S_FIFO_TX_LEVEL_WORD_8 | I2S_FIFO_RX_LEVEL_WORD_8;

    u32SrcClk = I2S_GetSourceClockFreq(i2s);

    u32BitRate = u32SampleRate * (((u32WordWidth>>4U) & 0x3U) + 1U) * 16U;
    //u16Divider = (uint16_t)((u32SrcClk/u32BitRate) >> 1U) - 1U;
    u16Divider = (uint16_t)((((u32SrcClk * 10UL / u32BitRate) >> 1U) + 5UL) / 10UL) - 1U;
    i2s->CLKDIV = (i2s->CLKDIV & ~I2S_CLKDIV_BCLKDIV_Msk) | ((uint32_t)u16Divider << 8U);

    /* calculate real sample rate */
    u32BitRate = u32SrcClk / (2U*((uint32_t)u16Divider+1U));
    u32SampleRate = u32BitRate / ((((u32WordWidth>>4U) & 0x3U) + 1U) * 16U);

    i2s->CTL0 |= I2S_CTL0_I2SEN_Msk;

    return u32SampleRate;
}

void I2S_Close(I2S_T *i2s)
{
    i2s->CTL0 &= ~I2S_CTL0_I2SEN_Msk;
}

void I2S_EnableInt(I2S_T *i2s, uint32_t u32Mask)
{
    i2s->IEN |= u32Mask;
}

void I2S_DisableInt(I2S_T *i2s, uint32_t u32Mask)
{
    i2s->IEN &= ~u32Mask;
}

uint32_t I2S_EnableMCLK(I2S_T *i2s, uint32_t u32BusClock)
{
    uint8_t u8Divider;
    uint32_t u32SrcClk, u32Reg, u32Clock;

    u32SrcClk = I2S_GetSourceClockFreq(i2s);
    if (u32BusClock == u32SrcClk)
    {
        u8Divider = 0U;
    }
    else
    {
        u8Divider = (uint8_t)(u32SrcClk/u32BusClock) >> 1U;
    }

    i2s->CLKDIV = (i2s->CLKDIV & ~I2S_CLKDIV_MCLKDIV_Msk) | u8Divider;

    i2s->CTL0 |= I2S_CTL0_MCLKEN_Msk;

    u32Reg = i2s->CLKDIV & I2S_CLKDIV_MCLKDIV_Msk;

    if (u32Reg == 0U)
    {
        u32Clock = u32SrcClk;
    }
    else
    {
        u32Clock = ((u32SrcClk >> 1U) / u32Reg);
    }

    return u32Clock;
}

void I2S_DisableMCLK(I2S_T *i2s)
{
    i2s->CTL0 &= ~I2S_CTL0_MCLKEN_Msk;
}

void I2S_SetFIFO(I2S_T *i2s, uint32_t u32TxThreshold, uint32_t u32RxThreshold)
{
    i2s->CTL1 = ((i2s->CTL1 & ~(I2S_CTL1_TXTH_Msk | I2S_CTL1_RXTH_Msk)) |
                 (u32TxThreshold << I2S_CTL1_TXTH_Pos) |
                 (u32RxThreshold << I2S_CTL1_RXTH_Pos));
}


void I2S_ConfigureTDM(I2S_T *i2s, uint32_t u32ChannelWidth, uint32_t u32ChannelNum, uint32_t u32SyncWidth)
{
    i2s->CTL0 = ((i2s->CTL0 & ~(I2S_CTL0_TDMCHNUM_Msk | I2S_CTL0_CHWIDTH_Msk | I2S_CTL0_PCMSYNC_Msk)) |
                 (u32ChannelWidth << I2S_CTL0_CHWIDTH_Pos) |
                 (u32ChannelNum << I2S_CTL0_TDMCHNUM_Pos) |
                 (u32SyncWidth << I2S_CTL0_PCMSYNC_Pos));
}
 /* end of group I2S_EXPORTED_FUNCTIONS */
 /* end of group I2S_Driver */
 /* end of group Standard_Driver */

/*** (C) COPYRIGHT 2016 Nuvoton Technology Corp. ***/