ADAU1701
Thread Summary
The user asks if Safeload registers can be used for real-time control of 2nd-order filter coefficients to change f0. The solution involves calculating the IIR coefficients using a provided spreadsheet, converting these coefficients to the required integer bytes for safeloading, and then safeloading the coefficients into the ADAU1701. Each coefficient must be padded with four binary zeros at the top and an added zero byte in the middle. The user confirms the solution is helpful.AI Generated Content
My application requires real-time control of General 2nd-Order Filter coefficients to change f0.
Can I use Safeload registers to do that?
How?
Best regards
Audio Signal Processors
SigmaDSP Audio Processors
adau1701
Hello lubo,
Here's an overview of the steps your microcontroller needs to do:
1. Calculate the coefficients -- See Brett's FAQ: https://ez.analog.com/docs/DOC-1819
He provides a spreadsheet that calculates the IIR coefficients. You could express the spreadsheet's formulas in your C code or else devise s lookup table -- either way works.
Test your coefficients by manually typing them into the IIR Coefficient Filter:
2. Convert your coefficients to the needed integer bytes for safeloading. NandoOne's post helps with this:
https://ez.analog.com/message/61175#61175
3. Have your microcontroller safeload the coefficients. Note that although the coefficients are each 3.5 bytes (28 bits) long, the ADAU1701 expects five bytes for each. Each coefficient has its top byte padded with four binary zeros, and includes an added zero byte in the middle. See:
https://ez.analog.com/thread/6429
Best regards,
Bob
Thanks a lot!
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