Skip to content

SGS Audio Debug SOP Manual

REVISION HISTORY

Revision No.
Description
 Date
1.0
  • Initial release
    		•  16/12/2024
    1.1
  • Modify keywords
    		•  06/10/2025

    Issue 1. Speaker Playback Silence

    Figure 1-1 Mind Map for Speaker Playback Silence Issue Localization
    Process Method
    Exit Condition
    Next Step
    Information Required by SWRD
    		 Relevant FAQ
    A During playback, use a multimeter to confirm whether AUDIO's AUDD18_AUD is 1.8V Exit Condition 1:
    1. During playback, AUDD18_AUD voltage differs significantly from 1.8V
    Exit Condition 2:
    2. During playback, AUDD18_AUD is stable at approximately 1.8V    		 Exit Condition 1:
    >External power supply issue exists, seek CAE assistance.
    Exit Condition 2:
    >External power supply is normal ==>B
    B Confirm whether the AMP pad padmux configuration matches the board (check if the amp pad on the EVB schematic matches the amp pad in padmux.dtis) Exit Condition 1:
    1.Pad is correct
    Exit Condition 2:
    2.Pad does not match the board    		 Exit Condition 1:
    >C
    Exit Condition 2:
    >Please modify the amp pad in padmux.dtsi accordingly
    C During playback, use a voltmeter to confirm whether the AMP pad can be pulled high and low normally
    		 Exit Condition 1:
    1.Can be pulled high and low normally
    Exit Condition 2:
    2. Cannot be pulled high and low    		 Exit Condition 1:
    >D
    Exit Condition 2:
    Trace routing abnormal    >Please seek CAE assistance for troubleshooting
    D Confirm whether the customer board AMP PAD is enabled by pull-high or pull-low Exit Condition 1:
    1.Pull-high enable
    Exit Condition 2:
    2.Pull-low enable    		 Exit Condition 1:
    >E
    Exit Condition 2:
    > Modify the parameter in the corresponding board's dtsi sound node node:amp-pad: change 1 to 0 indicating low-level enable
    E During playback, enable RDMA Singen to confirm whether sound can be output
    echo singen [SinGen Index][Enable] > /proc/mi_modules/mi_ao/mi_aox
    SinGen 0: Device0.
    SinGen 1: Device1.
    SinGen 2: Device2.
    SinGen 3: Device3.
    Example: echo singen 0 1 > /proc/mi_modules/mi_ai/mi_ai0, to enable singen for Device0    		 Exit Condition 1:
    1.Sound can be output
    Exit Condition 2:
    2. Sound cannot be output    		 Exit Condition 1:
    >H
    Exit Condition 2:
    >F
    F Cat mi proc info to confirm whether it is muted or if the gain value is set too small Exit Condition 1:
    1.Description issue exists
    Exit Condition 2:
    2. No description issue    		 Exit Condition 1:
    ==> Confirm settings with customer
    Exit Condition 2:
    ==> G
    G During playback, use an oscilloscope to capture the lineout output while RDMA Singen is enabled Exit Condition 1:
    1.lineout has signal
    Exit Condition 2:
    2.lineout has no signal    		 Exit Condition 1:
    >Seek CAE assistance to confirm if it is an amplifier issue
    Exit Condition 2:
    >After confirming that the oscilloscope captured no signal from the chip output, seek SW RD assistance    		 Whether the issue can be reproduced on the reference board, environment setup method
    H Dump user data to confirm whether the written data is normal Exit Condition 1:
    Dump data is normal
    Exit Condition 2:
    Dump data is abnormal    		 Exit Condition 1:
    > Seek SW RD assistance
    Exit Condition 2:
    > Investigate customer app issues    		 Confirm whether the issue can be reproduced on the reference board, the environment to reproduce the issue, and the method to reproduce the issue
    ---

    Issue 2. AMIC Recording No Data

    Figure 2-1 Mind Map for AMIC Recording No Data Issue Localization
    Process Method
    Exit Condition
    Next Step
    Information Required by SWRD
    		 Relevant FAQ
    A Enable Amic Sinegen during recording to confirm whether a sine wave can be recorded (refer to MI_AI documentation for Singen enable method) Exit Condition 1:
    1.No sound recorded
    Exit Condition 2:
    2. Sound can be recorded    		 Exit Condition 1:
    Most likely a software issue, perform software troubleshooting==>C
    Exit Condition 2:Most likely a hardware issue, perform hardware troubleshooting==>B
    B Seek CAE to confirm hardware issues, including Audio 1.8V power supply, AMIC bias, and AMIC wiring location, as well as other hardware-related issues
    		 Exit Condition 1:
    1.Hardware confirmed no issues
    Exit Condition 2:
    2.Hardware issue found    		 Exit Condition 1:
    ==>D
    Exit Condition 2:
    CAE assistance
    C Cat mi proc info to confirm whether the AI interface is muted Exit Condition 1:
    1.No mute
    Exit Condition 2:
    2. Mute exists    		 Exit Condition 1:
    ==> Seek SW RD for analysis
    Exit Condition 2:
    Investigate customer APP settings    		 Confirm whether the issue can be reproduced on the reference board, the environment to reproduce the issue, and the method to reproduce the issue

    Issue 3. I2S Codec Adaptation Issues

    Figure 3-1 Mind Map for I2S Master Mode Operation Abnormality Issue Localization
    Process Method
    Exit Condition
    Next Step
    Information Required by SWRD
    		 Relevant FAQ
    A Confirm whether the AUDIO I2S PAD padmux configuration matches the development board, and whether the pad conflicts with other modes Method:
    cd
    vim arch/arm/boot/dts/xxx_xxxx-padmux.dtsi
    Search for whether I2S PAD has been switched to MDRV_PUSE_I2S0_XX_XXX mode, and use IO_Check Tool to check if the mode setting is successful (./io_check_xxx PinID)
    		 Exit Condition 1:
    1.padmux is not correctly configured or conflicts with other modes
    Exit Condition 2:
    2.I2S PAD configuration is normal
    		 Exit Condition 1:
    >Assist customer in modifying padmux settings
    Exit Condition 2:
    > B
    B Run mi_demo prog_audio_audio corresponding I2S case and use an oscilloscope to capture Tx or Rx signals Exit Condition 1:
    Normal tx rx clk data signals can be captured
    Exit Condition 2:
    No signal can be captured, or signal is abnormal    		 Exit Condition 1:
    >C
    Exit Condition 2:
    > Seek CAE to confirm pad trace routing issues and interference issues
    C Confirm whether the chip-side I2S mode format and other formats match the customer codec, refer to MI API documentation Exit Condition 1:
    Format is normal
    Exit Condition 2:
    Format is abnormal    		 Exit Condition 1:
    >D
    Exit Condition 2:
    >Assist customer in modifying I2S format
    D Confirm whether the wiring sequence connected to the codec is correct, and whether there is common ground
    In 6-wire mode:
    TX_BCK<>RX_BCK
    TX_WCK<    >RX_WCK
    TX_SDO<>RX_SDI
    PS:codec's LRCK is WCK
    In 4-wire mode:
    RX_BCK<    >RX_BCK
    RX_WCK<>RX_WCK
    RX_SDI<    >TX_SD0
    TX_SD0<==>RX_SDI    		 Exit Condition 1:
    Wiring sequence is normal, common ground exists
    Exit Condition 2:
    Wiring sequence is abnormal, no common ground    		 Exit Condition 1:
    ==> E
    Exit Condition 2:
    ==>Assist customer in confirming wiring sequence issues
    E Confirm whether the selected pad voltage domain 1.8V/3.3V matches the customer codec Exit Condition 1:
    Voltage matches
    Exit Condition 2:
    Voltage does not match    		 Exit Condition 1:
    ==> Compile customer codec information, Tx Rx waveform signals, seek SW RD assistance for troubleshooting
    Exit Condition 2:Seek CAE to confirm the method to switch to the corresponding pad voltage domain
    ---

    Issue 4. DMIC Operation Abnormality Issues

    Figure 4-1 Mind Map for DMIC Operation Abnormality Issue Localization
    Process Method
    Exit Condition
    Next Step
    Information Required by SWRD
    		 Relevant FAQ
    A Confirm whether the AUDIO DMIC PAD padmux configuration matches the development board, and whether the pad conflicts with other modes Method:
    cd
    vim arch/arm/boot/dts/xxx_xxxx-padmux.dtsi
    Search for whether DMIC PAD has been switched to MDRV_PUSE_DMIC0_XX mode, and use IO_Check Tool to check if the mode setting is successful (./io_check_xxx PinID)
    		 Exit Condition 1:
    >padmux is not correctly configured or conflicts with other modes
    Exit Condition 2:
    >DMIC PAD configuration is normal
    		 Exit Condition 1:
    >Assist customer in confirming padmux issues
    Exit Condition 2:
    > B
    B Run prog_audio_audio dmic demo and capture DMIC BCK and DMIC data
    		 Exit Condition 1:
    1.BCK 2.4M and Data has data
    Exit Condition 2:
    No BCK, no Data
    Exit Condition 3:
    Has BCK, no Data    		 Exit Condition 1:
    ==>C
    Exit Condition 2:
    Seek CAE to confirm whether trace routing issues exist
    Exit Condition 3:
    Seek CAE to confirm whether DMIC is damaged
    C Confirm whether the wiring sequence is correct
    DMIC wiring sequence is relatively simple, mainly CLK, data, power, and ground    		 Exit Condition 1:
    Wiring sequence is correct
    Exit Condition 2:
    Wiring sequence is incorrect    		 Exit Condition 1:
    ==>D
    Exit Condition 2:
    Assist customer in clarifying wiring sequence
    D Confirm whether DMIC hardware is 3.3V or 1.8V, and confirm whether the currently selected pad is 3.3V or 1.8V, voltages need to match Exit Condition 1:
    1.Voltages match
    Exit Condition 2:
    2. Voltages do not match    		 Exit Condition 1:
    > Compile the environment to reproduce the issue, confirm whether customer dmic spec can reproduce the issue on the reference board, seek SW RD assistance
    Exit Condition 2:
    > Seek CAE to confirm the voltage domain adjustment method    		 Customer DMIC spec
    Reference board reproduction environment

    Issue 5. AI Interface Known Issues FAQ

    5.1 AI Unable to Retrieve Data Issue

    Based on the specific scenario, capture the device's proc information to view the current buffer configuration and usage. cat /proc/mi_modules/mi_ai/mi_aix

    Confirm the output buffer configuration. usrDepth and BufCntQuota represent the number of buffers available to the application and the total number of buffers, respectively. Check whether usrDepth and BufCntQuota are set to 0.

    Confirm the buffer retrieval status by the application. usrLockedCnt indicates the number of buffers held by the application without release. If usrLockedCnt equals usrDepth, it indicates that the application has captured all available output buffers.

    5.2. Buffer Interval Instability (Buffer Loss)

    Based on the specific scenario, capture the device's proc information to view the current buffer configuration and usage. cat /proc/mi_modules/mi_ai/mi_aix

    • Confirm the output buffer configuration. usrDepth and BufCntQuota represent the number of buffers available to the application and the total number of buffers, respectively. Check whether usrDepth and BufCntQuota are too small, causing buffer retrieval by the application to affect normal AI thread operation.
    • If buffers are sufficient but GetFrame/Ms and FPS are significantly lower than expected, compile the information and contact the audio owner.

    5.3. Sound Clipping with Normal Sampling Values

    This issue is commonly observed in AMIC and DMIC interfaces. Both interfaces have interface gain and DPGA gain in their signal paths. A common scenario is that the interface gain is set too high causing clipping, and then attenuation is applied through DPGA gain, causing the sampling values to return to the normal range.

    5.4. AMIC Pop Noise Issue

    Root Cause: The ADC reference capacitor needs to charge to 0.9V. Recording with the ADC before the capacitor is fully charged results in noise, which is pop noise.

    Solution:

    • For chips after ifackel, a fast charging design for the capacitor has been added. The default code includes a 50ms delay, so this issue does not occur.

    • For chips before ifackel, it is necessary to enable keep adc on in dtsi to resolve this issue by increasing power consumption.

    • In fast boot scenarios where time is critical and delay is not desired, enable SGS_BACH SGS_BACH_FAST_BOOT in IPL to resolve the issue by enabling ADC reference capacitor charging during IPL.

    5.5. DMIC Pop Noise Issue

    There are two root causes:

    1. DMIC hardware cannot provide valid data immediately after receiving BCK. Typically, it takes approximately 10ms to output valid data. This abnormal data will be received by the IC and accumulated to an abnormal value, resulting in pop noise.

    2. Many DMIC hardware devices have DC bias. The internal HPF module of the IC can pull the DC bias back to the median value, but this process takes time. The presence of bias also causes pop noise.

    Solution:

    • Add dmic-delay = <80> field to the dtsi sound node; The parameter 80 represents the delay time. By delaying for 80ms, the pop noise issue is avoided.

    Issue 6. AO Interface Known Issues FAQ

    6.1. DAC Pop Noise Issue

    There are two root causes:

    1. Voltage change at the moment of DAC activation
    2. The DAC reference capacitor requires time to charge. Activating the DAC before it is fully charged also results in sound abnormality.

    Solution:

    • For chips after ifackel, a fast charging design for the capacitor has been added. By delaying for 50ms to wait for capacitor charging completion, the voltage change at DAC activation is also avoided. The amplifier pad is then activated, and the DAC pop noise issue is resolved through amp mute.

    • For chips before ifackel, it is necessary to enable keep dac on in dtsi to resolve this issue by increasing power consumption.

    Issue 7. Noise Issue When Speaker Amplifier Gain is Adjusted to 9x

    Issue Background: For Pcupid customers with 1.8V IO, the amplifier gain is adjusted to 9x to meet expected output power. During program execution, noise can be heard from the speaker. At this time, audio is not enabled. Only the amplifier is enabled.

    Root Cause: When CPU loading is high, internal current noise from the chip couples from GND to the amplifier. When the amplifier is enabled, noise can be heard.

    Solution: This issue can only be resolved by using a differential amplifier to address GND noise. Since both input signals of the differential amplifier carry noise, the noise can be eliminated through differential processing. Additionally, request CAE to change the Audio AUD_VRM pad grounding to a relatively clean GND, similar to that of the amplifier.