I have modified the ADC_DAC_Playback Example project to get TDM4 and also TDM8 working.

Then I added the USB Audio DEMO for ADSP-SC573 and modified the configuration settings for ADAU1962A (TDM8) and the audio is distorted.

The best way to describe this is that is sounds tinny (metalic) but all the audio channels are correct.

I have examined DBCLK, DLRCLK, DSDATA1 on the scope and this is how I confirmed that TDM8 looks to be working correctly here.

I am happy to share project if required.

Note I have sent previous requests to support & I have open support tickets but I've not had any response for a while so I'm hoping this proves more fruitful.

Thanks in advance,


  • Hi Dave,

    Apologies for my ignorance, I am only a few months into working with hardware, so I thoroughly appreciate you taking the time to aide me in whatever way possible.

    For explicity's sake I have modified function adi_adau1962a_ConfigSerialClk to show bool values and settings (image attached as it's easier to read than the code pasted in):

    I think you mean DAC register settings in file adi_adau1962a_regs.h, correct? if so, see below:

    If not, can you please detail how to get the information you need?

    Many Thanks,


    /* PLL and Clock control 0 Register field definitions (ADI_ADAU1962A_REG_PLL_CLK_CTRL0) */
    #define BITM_ADAU1962A_00_PLL_IN (0xC0u) /* PLL Input */
    #define ENUM_ADAU1962A_00_PLL_IN_DLRCLK (0x40u) /* DLRCLK */
    #define ENUM_ADAU1962A_00_PLL_IN_MCLKI (0x00u) /* MCLKI/XI */

    #define BITM_ADAU1962A_00_XTAL_SET (0x30u) /* XTALO pin status */
    #define ENUM_ADAU1962A_00_XTAL_OSC_OFF (0x30u) /* XTAL Oscillator Off */
    #define ENUM_ADAU1962A_00_XTAL_OSC_ON (0x00u) /* XTAL oscillator On */

    #define BITM_ADAU1962A_00_SOFT_RST (0x08u) /* Soft-Reset control */
    #define ENUM_ADAU1962A_00_SOFT_RST_EN (0x08u) /* Enable Soft-Reset */
    #define ENUM_ADAU1962A_00_SOFT_RST_CLR (0x00u) /* Clear Soft-Reset */

    #define BITP_ADAU1962A_00_MCLK_SEL (1u) /* MCLK Select position */
    #define BITM_ADAU1962A_00_MCLK_SEL (0x06u) /* MCLK pin functionality (PLL active) Mask */
    #define ENUM_ADAU1962A_00_MCLK_SEL_768 (0x06u) /* INPUT 768 (x 44.1 kHz or 48 kHz) */
    #define ENUM_ADAU1962A_00_MCLK_SEL_512 (0x04u) /* INPUT 512 (x 44.1 kHz or 48 kHz) */
    #define ENUM_ADAU1962A_00_MCLK_SEL_384 (0x02u) /* INPUT 384 (x 44.1 kHz or 48 kHz) */
    #define ENUM_ADAU1962A_00_MCLK_SEL_256 (0x00u) /* INPUT 256 (x 44.1 kHz or 48 kHz) */

    #define BITM_ADAU1962A_00_MSTR_PWR (0x01u) /* Master Power-Up Control */
    #define ENUM_ADAU1962A_00_MSTR_PWR_UP (0x01u) /* Master Power-Up */
    #define ENUM_ADAU1962A_00_MSTR_PWR_DN (0x00u) /* Master Power-Down */

    /* PLL and Clock control 1 Register field definitions (ADI_ADAU1962A_REG_PLL_CLK_CTRL1) */
    #define BITM_ADAU1962A_01_LOPWR_MODE (0xC0u) /* Global Power/Performance Adjust */
    #define ENUM_ADAU1962A_01_LOPWR_MODE_LOWEST (0xC0u) /* Lowest Power */
    #define ENUM_ADAU1962A_01_LOPWR_MODE_LOWER (0x80u) /* Lower Power */
    #define ENUM_ADAU1962A_01_LOPWR_MODE_I2C (0x00u) /* I2C Register Settings */

    #define BITM_ADAU1962A_01_MCLKO_SEL (0x30u) /* MCLK Output Frequency */
    #define ENUM_ADAU1962A_01_MCLKO_DIS (0x30u) /* MCLKO Pin Disabled */
    #define ENUM_ADAU1962A_01_MCLKO_MCLKI (0x20u) /* Buffered MCLKI */
    #define ENUM_ADAU1962A_01_MCLKO_8_12MHZ (0x10u) /* 8 MHz to 12 MHz scaled by fs */
    #define ENUM_ADAU1962A_01_MCLKO_4_6MHZ (0x00u) /* 4 MHz to 6 MHz scaled by fs */

    #define BITM_ADAU1962A_01_PLL_MUTE (0x08u) /* PLL Automute Enable/Lock */
    #define ENUM_ADAU1962A_01_PLL_MUTE_EN (0x08u) /* DAC Automute on PLL Unlock */
    #define ENUM_ADAU1962A_01_PLL_MUTE_DIS (0x00u) /* No DAC Automute */

    #define BITM_ADAU1962A_01_PLL_LOCK (0x04u) /* PLL Lock Indicator */
    #define ENUM_ADAU1962A_01_PLL_LOCKED (0x00u) /* PLL Locked */

    #define BITM_ADAU1962A_01_VREF_EN (0x02u) /* Internal Voltage Reference Enable */
    #define ENUM_ADAU1962A_01_VREF_EN (0x02u) /* VREF Enabled */
    #define ENUM_ADAU1962A_01_VREF_DIS (0x00u) /* VREF Disabled */

    #define BITM_ADAU1962A_01_DAC_CLK_SEL (0x01u) /* DAC Clock Select */
    #define ENUM_ADAU1962A_01_DAC_CLK_MCLKI (0x01u) /* MCLK from MCLKI or XTALI as DAC Clock Source */
    #define ENUM_ADAU1962A_01_DAC_CLK_PLL (0x00u) /* PLL as DAC Clock Source */

    /* Block Power-down and Thermal Sensor Control 1 Register field definitions (ADI_ADAU1962A_REG_PDN_THRMSENS_CTRL_1) */
    #define BITM_ADAU1962A_02_THRM_RATE (0xC0u) /* Conversion Time Interval */
    #define ENUM_ADAU1962A_02_THRM_RATE_2S (0xC0u) /* 2 sec/Conversion */
    #define ENUM_ADAU1962A_02_THRM_RATE_1S (0x80u) /* 1 sec/Conversion */
    #define ENUM_ADAU1962A_02_THRM_RATE_0_5_S (0x40u) /* One-Shot Mode */
    #define ENUM_ADAU1962A_02_THRM_RATE_4S (0x00u) /* 4 sec/Conversion */

    #define BITM_ADAU1962A_02_THRM_MODE (0x20u) /* One-Shot Conversion Mode */
    #define ENUM_ADAU1962A_02_THRM_MODE_ONE_SHOT (0x20u) /* One-Shot Mode */
    #define ENUM_ADAU1962A_02_THRM_MODE_CONTINUOUS (0x00u) /* Continuous Operation */

    #define BITM_ADAU1962A_02_THRM_GO (0x10u) /* One-Shot Conversion Mode */
    #define ENUM_ADAU1962A_02_THRM_GO_CONVERT (0x10u) /* Convert Temperature */
    #define ENUM_ADAU1962A_02_THRM_GO_RESET (0x00u) /* Reset */

    #define BITM_ADAU1962A_02_TS_PDN (0x04u) /* Temperature Sensor Power-Down */
    #define ENUM_ADAU1962A_02_TS_PDN_PDN (0x04u) /* Temperature Sensor Power-Down */
    #define ENUM_ADAU1962A_02_TS_PDN_NORMAL (0x00u) /* Temperature Sensor Normal Operation */

    #define BITM_ADAU1962A_02_PLL_PDN (0x02u) /* PLL Power-Down */
    #define ENUM_ADAU1962A_02_PLL_PDN_PDN (0x02u) /* PLL Power-Down */
    #define ENUM_ADAU1962A_02_PLL_PDN_NORMAL (0x00u) /* PLL Normal Operation */

    #define BITM_ADAU1962A_02_VREG_PDN (0x01u) /* Voltage Regulator Power-Down */
    #define ENUM_ADAU1962A_02_VREG_PDN_PDN (0x01u) /* Voltage Regulator Power-Down */
    #define ENUM_ADAU1962A_02_VREG_PDN_NORMAL (0x00u) /* Voltage Regulator Normal Operation */

    /* Bit mask for power-down control */
    #define BITM_ADAU1962A_02_PDN_CTRL (BITM_ADAU1962A_02_TS_PDN |\
    BITM_ADAU1962A_02_PLL_PDN |\

    /* Power-Down control 2 Register field definitions (ADI_ADAU1962A_REG_PDN_CTRL2) */
    #define BITM_ADAU1962A_03_DAC_PDN (0x01u) /* Power-Down DAC Channel */
    #define ENUM_ADAU1962A_03_DAC_PDN_PDN (0x01u) /* Power-Down DAC Channel */
    #define ENUM_ADAU1962A_03_DAC_PDN_NORMAL (0x00u) /* Normal Operation */

    /* DAC control 0 Register field definitions (ADI_ADAU1962A_REG_DAC_CTRL0) */
    #define BITM_ADAU1962A_06_SDATA_FMT (0xC0u) /* SDATA Format */
    #define ENUM_ADAU1962A_06_SDATA_FMT_I2S (0x00u) /* I2S, 1 BCLK Cycle Delay */

    #define BITM_ADAU1962A_06_SAI (0x38u) /* Serial Audio Interface */
    #define ENUM_ADAU1962A_06_SAI_TDM16 (0x20u) /* TDM16—Single Line (48 kHz) */
    #define ENUM_ADAU1962A_06_SAI_TDM8 (0x18u) /* TDM8—Dual Line */
    #define ENUM_ADAU1962A_06_SAI_TDM4 (0x10u) /* TDM4—Quad Line */
    #define ENUM_ADAU1962A_06_SAI_TDM2 (0x08u) /* TDM2—Octal Line */
    #define ENUM_ADAU1962A_06_SAI_STEREO (0x00u) /* Stereo (I2S, LJ, RJ) */

    #define BITP_ADAU1962A_06_FS (1u) /* Sample Rate Select */
    #define BITM_ADAU1962A_06_FS (0x06u) /* Mask for Sample Rate Select */
    #define ENUM_ADAU1962A_06_FS_128_176_192_LOW (0x06u) /* 128 kHz/176.4 kHz/192 kHz Low Propagation Delay */
    #define ENUM_ADAU1962A_06_FS_128_176_192 (0x04u) /* 128 kHz/176.4 kHz/192 kHz */
    #define ENUM_ADAU1962A_06_FS_64_88_96 (0x02u) /* 64 kHz/88.2 kHz/96 kHz */
    #define ENUM_ADAU1962A_06_FS_32_44_48 (0x00u) /* 32 kHz/44.1 kHz/48 kHz */

    #define BITM_ADAU1962A_06_MMUTE (0x01u) /* Master Mute */
    #define ENUM_ADAU1962A_06_MMUTE_EN (0x01u) /* All Channels Muted */
    #define ENUM_ADAU1962A_06_MMUTE_DIS (0x00u) /* Normal Operation */

    /* DAC control 1 Register field definitions (ADI_ADAU1962A_REG_DAC_CTRL1) */
    #define BITM_ADAU1962A_07_BCLK_GEN (0x80u) /* DBCLK Generation */
    #define ENUM_ADAU1962A_07_BCLK_GEN_INTERNAL (0x80u) /* Internal DBCLK Generation */
    #define ENUM_ADAU1962A_07_BCLK_GEN_NORMAL (0x00u) /* Normal Operation—DBCLK */

    #define BITM_ADAU1962A_07_LRCLK_MODE (0x40u) /* DLRCLK Mode Select. Only Valid for TDM modes */
    #define ENUM_ADAU1962A_07_LRCLK_PULSE (0x40u) /* Pulse mode */
    #define ENUM_ADAU1962A_07_LRCLK_50_50 (0x00u) /* 50% Duty Cycle DLRCLK */

    #define BITM_ADAU1962A_07_LRCLK_POL (0x00u) /* DLRCLK Polarity. Allows the swapping of data between channels */
    #define ENUM_ADAU1962A_07_LRCLK_POL_INVERT (0x20u) /* Left/Odd channels are DLRCLK High (Inverted) */
    #define ENUM_ADAU1962A_07_LRCLK_POL_NORMAL (0x00u) /* Left/Odd channels are DLRCLK Low (Normal) */

    #define BITM_ADAU1962A_07_SAI_MSB (0x10u) /* MSB Position */
    #define ENUM_ADAU1962A_07_SAI_LSB_FIRST (0x10u) /* LSB First DSDATA */
    #define ENUM_ADAU1962A_07_SAI_MSB_FIRST (0x00u) /* MSB First DSDATA */

    #define BITM_ADAU1962A_07_BCLK_RATE (0x04u) /* DBCLK Rate. Number of DBCLK cycles per DLRCLK frame */
    #define ENUM_ADAU1962A_07_BCLK_RATE_16CYCLES (0x04u) /* 16 Cycles per Frame */
    #define ENUM_ADAU1962A_07_BCLK_RATE_32CYCLES (0x00u) /* 32 Cycles per Frame */

    #define BITM_ADAU1962A_07_BCLK_EDGE (0x02u) /* DBCLK Active Edge */
    #define ENUM_ADAU1962A_07_BCLK_FALLING_EDGE (0x02u) /* Latch on Falling Edge */
    #define ENUM_ADAU1962A_07_BCLK_RISING_EDGE (0x00u) /* Latch on Rising Edge */

    #define BITM_ADAU1962A_07_SAI_MS (0x01u) /* Serial Interface Master */
    #define ENUM_ADAU1962A_07_SAI_MASTER (0x01u) /* DLRCLK/DBCLK Master */
    #define ENUM_ADAU1962A_07_SAI_SLAVE (0x00u) /* DLRCLK/DBCLK Slave */

    /* DAC control 2 Register field definitions (ADI_ADAU1962A_REG_DAC_CTRL2) */
    #define BITM_ADAU1962A_08_BCLK_TDMC (0x20u) /* DBCLK Rate in TDM Mode */
    #define ENUM_ADAU1962A_08_BCLK_TDMC_16 (0x20u) /* 16 BCLK cycles/channel slot */
    #define ENUM_ADAU1962A_08_BCLK_TDMC_32 (0x00u) /* 32 BCLK cycles/channel slot */

    #define BITM_ADAU1962A_08_DAC_POL (0x10u) /* DAC Output Polarity. This is a global switch of DAC polarity */
    #define ENUM_ADAU1962A_08_DAC_POL_INVERT (0x10u) /* Inverted DAC Output */
    #define ENUM_ADAU1962A_08_DAC_POL_NON_INVERT (0x00u) /* NonInverted DAC Output */

    #define BITM_ADAU1962A_08_AUTO_MUTE_EN (0x04u) /* Automute Enable */
    #define ENUM_ADAU1962A_08_AUTO_MUTE_EN (0x04u) /* Auto-Zero Input Mute Enabled */
    #define ENUM_ADAU1962A_08_AUTO_MUTE_DIS (0x00u) /* Auto-Zero Input Mute Disabled */

    #define BITM_ADAU1962A_08_DAC_OSR (0x02u) /* DAC Oversampling Rate. OSR selection */
    #define ENUM_ADAU1962A_08_DAC_OSR_128 (0x02u) /* 128 × fs DAC Oversampling */
    #define ENUM_ADAU1962A_08_DAC_OSR_256 (0x00u) /* 256 × fs DAC Oversampling */

    #define BITM_ADAU1962A_08_DE_EMP_EN (0x01u) /* De-Emphasis Enable */
    #define ENUM_ADAU1962A_08_DE_EMP_EN (0x01u) /* De-Emphasis Enabled */
    #define ENUM_ADAU1962A_08_DE_EMP_DIS (0x00u) /* No De-Emphasis/Flat */

    /* DAC Individual channel mutes 1 Register field definitions (ADI_ADAU1962A_REG_DAC_MUTE1) */
    #define BITM_ADAU1962A_09_DAC_MUTE (0x01u) /* Mute DAC Channel */
    #define ENUM_ADAU1962A_09_DAC_MUTE_EN (0x01u) /* Mute DAC Channel */
    #define ENUM_ADAU1962A_09_DAC_MUTE_DIS (0x00u) /* Normal Operation, Mute disabled */

    /* Pad strength Register field definitions (ADI_ADAU1962A_REG_PAD_STRGTH) */
    #define BITM_ADAU1962A_1C_PAD_DRV (0x20u) /* Output Pad Drive Strength Control */
    #define ENUM_ADAU1962A_1C_PAD_DRV_8MA (0x20u) /* 8 mA Drive for All Pads */
    #define ENUM_ADAU1962A_1C_PAD_DRV_4MA (0x00u) /* 4 mA Drive for All Pads */

    /* DAC Power adjust 1 Register field definitions (ADI_ADAU1962A_REG_DAC_POWER1) */
    #define BITM_ADAU1962A_1D_DAC_POWER (0x03u) /* DAC Power Control */
    #define ENUM_ADAU1962A_1D_DAC_GOOD_PERF (0x03u) /* Good Performance */
    #define ENUM_ADAU1962A_1D_DAC_BEST_PERF (0x02u) /* Best Performance */
    #define ENUM_ADAU1962A_1D_DAC_LOWEST_POWER (0x01u) /* Lowest Power */
    #define ENUM_ADAU1962A_1D_DAC_LOW_POWER (0x00u) /* Low Power */

  • 0
    •  Analog Employees 
    on May 2, 2019 7:10 PM in reply to andy@sr

    Hello Andrew,

    My apologies with not being clear enough.

    Read the registers in the DAC, registers at addresses 0x00 to 0x1F and send me the results. No code, just 8-bit hex numbers. There are 27 registers. 

    All the defines you listed are for writing to the DAC. I want to know what the result was once all the writes have happened. 


    Dave T

  • Hi Dave,

    Apologies from my .xlsx document being incorrect, I have been checking over the registers and it seems the values outputted by the function I used wasn't accurate, something I tried to confirm and avoid.

    That said, I hope I haven't wasted any of your time by having you check those values.

    I found an example of where to read the registers and hopefully this better explains what I'm actually getting and allows you to offer some helpful advice.

    Kind regards,


  • Hi Dave, me again... (apologies)

    So we have solved one issue:
    Turns out the audio distortion was due to clipping.
    After using Reaper and reducing the levels for each audio channel by -6dB the distortion cleared.
    This led us back to the DAC and specifically the DAC Control Register 0, specifically SDATA_FMT.
    Referring to the Data sheet for the ADAU_1962a (p.30)
    The value for SDATA was set to (0x18u) I2S by the value ENUM_ADAU1962A_06_SAI_TDM8 in adi_adau1962_regs.h
    We modified this value to be Left Justified, chaning the register value to (0x58u) and the audio immediately became clear.

    The final issue is that the L/R channels remain swapped.
    Do you have any advice as to what we should be look for when trying to remedy this issue?

    Many thanks,

  • 0
    •  Analog Employees 
    on May 16, 2019 4:23 PM in reply to andy@sr

    Hello Andrew,

    DAC_CTRL1 register, bit 5, is for LRCLK polarity. Flip that bit and the channels will swap. 

    Dave T