Noise when reading the program store
we have an application where we have to read the program store and verify the contents, however when we do this there is an occasional popping noise in the outputs, we are currently only reading the store when the system is not passing audio, but this is a workaround we are not happy with.
I saw another post https://ez.analog.com/dsp/sigmadsp/f/q-a/66498/pop-noise-when-reading-from-adau1701 which was not answered so the problem has been around a while
Thanks in advance
Audio Signal Processors
noise
SigmaDSP Audio Processors
adau1701
Hi AnthonyCSmith
Always disable DACs before your full read or write to DSP, this will prevent any unwanted noise and can be done with the folow:
1) Disable DAC: You have two options
a) Read Core register value, then clear DAM bit (D3), write it to DSP at 0x081C ( Best option )
b) Read core Regiter, save value for later, then Write ( 0x00 0x14 ) to 0x081C
2) Read or write entire program/parameters
3) Enable DAC: You have two options
b) Read Core register value, then set DAM bit (D3), write it to DSP at 0x081C ( Best option )
a) Restore Core Register value that you have readed before
Also, ween you write to Parameters Register ( 0x0000 to 0x3FFF ), do it everytime using Safeload.
This can be found at page 40 of datasheet at ADAU1401.pdf
This doesn't solve my problem, why when reading the DSP does it generate noise in the DACs?
Hi AnthonyCSmith
Could you please provide a step-by-step method of reproducing the problem? also what board you have,
Did u try with an oficial AD EVAL board?
We are using the chip in a voice alarm product, so we must check the code store periodically; reading the ADAU1701 EVAL board also produces noise in the DA outputs. On further investigation it is the internal DACs that the noise is on but not the I2S pass through or I2S DACs?
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