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AIC3254 - NR module

Micky52259
Intellectual 765 points

Hi,

I've made the following app:

I want to operate at 16 kHz. Therefore I added the command file as "execute on reset" in my project as below. I now encounter the following problems:

1. At 16 kHz this is not working (I hear loud noise), it operates at 44.1 kHz. At least I can hear some audio data, then. At 8 kHz the device is operating, too. Is so, that the NR does not operate at this frequency?

2. The microphone input is not working - I only have the Line-input.

Any help is welcome.

Micky

 

 

My I2C-Command File is (as provided by Texas)-

###############################################
# Power Down Sequence
###############################################
#
# Select Page 1
w 30 00 01
#
# Power Down HP/LO Amps
w 30 09 00
#
# Select Page 1
w 30 00 00
#
# Power Down DACs
w 30 3F 14
w 30 40 0C
#
# Power Down ADCs
w 30 51 00
#
###############################################


###############################################
# Configure Power Supplies
###############################################
#
# Select Page 1
w 30 00 01
#
# Power up AVDD LDO
w 30 02 A9
#
# Disable weak AVDD in presence of external
# AVDD supply
w 30 01 08
#
# Enable Master Analog Power Control
# Power up AVDD LDO
w 30 02 A1
#
# Set the input power-up time to 3.1ms (for ADC)
w 30 47 32
#
# Set the REF charging time to 40ms
w 30 7b 01
#
###############################################


###############################################
# Configure ADC Channel
###############################################
#
# Select Page 1
w 30 00 01
#
# Route IN2L to LEFT_P with 10K input impedance
w 30 34 10
#
# Route CM1L to LEFT_M with 10K input impedance
w 30 36 40
#
# Route IN2R to RIGHT_P with 10K input impedance
w 30 37 10
#
# Route CM1R to RIGHT_M with 10K input impedance
w 30 39 40
#
# Unmute Left MICPGA, Gain selection of 0dB to
# make channel gain 0dB, since 10K input
# impedance is used single ended
w 30 3b 00
#
# Unmute Right MICPGA, Gain selection of 0dB to
# make channel gain 0dB, since 10K input
# impedance is used single ended
w 30 3c 00
#
# Select Page 0
w 30 00 00
#
# Power up LADC/RADC
w 30 51 c0
#
# Unmute LADC/RADC
w 30 52 00
#
###############################################

###############################################
# Playback Setup
###############################################
#
# Select Page 1
w 30 00 01
#
# De-pop: 16 time constants, 6k resistance
w 30 14 35
#
# Route LDAC/RDAC to HPL/HPR
w 30 0c 08 08
#
# Route LDAC/RDAC to LOL/LOR
w 30 0e 08 08
#
# Power up HPL/HPR and LOL/LOR drivers
w 30 09 3C
#
# Unmute HPL/HPR driver, 0dB Gain
w 30 10 00 00
#
# Unmute LOL/LOR driver, 0dB Gain
w 30 12 00 00
#
# Select Page 0
w 30 00 00
#
# DAC => 0dB
w 30 41 00 00
#
# Power up LDAC/RDAC
w 30 3f d6
#
# Unmute LDAC/RDAC
w 30 40 00
#
###############################################

  • 0
    TI__Mastermind 46195 points

    Micky,

    The default configuration for the EVM is for 44.1kHz sampling. You would need to re-configure the clock and PLL settings for 16ksps. See http://www.ti.com/litv/pdf/slaa404c for sample scripts (for 8ksps). For 16ksps, DOSR must should be 384 and AOSR should be 128. See the Firmware Upgrade document in the USBfirmware directory of the PurePath Installation folder for MCLK, BCLK, and WCLK rates for each sample rate. For 16ksps the firmware needs to be re-programmed.

    The newest version of PurePath (4.10) allows you to edit the Page 0 and Page 1 registers in the framework. This is on the SystemSettingsCode property of the framework. With this feature, there is no need to use the patch above. You would just modify p1_r2 for LDO use and the analog input routing for IN2 instead of IN1. 

    Regards,

    J-

  • 0 in reply to J-
    Intellectual 765 points

    Hi J. ,

    I thought the AIC3254_SystemSettingsCode does at least find the proper setup (see, there is a "%%if (%%prop(SampleRate) == 16000)" instruction in the Frame-work code above (I have the 4.10 version). I copied this Framework to the mentioned Framework setting.

    I switched back to the Orginalfile of the Framework and now added

    reg[0][12] = 0x98                       ; MDAC

    reg[0][19] = 0x98

    So now I got the 16 kHz Signal (At least I think so). Now the noise has gone. Last thing to do now is to change the routing...

    Regards.

    Michael

  • 0 in reply to Micky52259
    TI__Mastermind 46195 points

    Michael,

    The AIC3254_SystemSettingsCode should take care of it. I forgot that I provided you that file in a different post.

    When using the AIC3254_SystemSettingsCode, set the project sample rate to 16ksps and upgrade the firmware.This will set the correct frequencies for I2S and Windows will also recognize it as 16ksps after re-connecting the USB.

    Modifying the M values only will not work properly (you will get out of band noise in the audible range of the DAC side).

    Regards,

    J-