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STA350BW write coefficients

joern23
Associate
Posted on January 15, 2015 at 18:00

hi all,

i am building an demo application that works right from powering up.

Therefore i added an I2C Master to the STEVAL-CCA035V1 and STEVAL-CCA030V1.

I can succesfully write the registers of the device and i can also verify that with the APWorkbench.

But i am having problems with the coefficients...

I dont know why but at first power up everything is working except the equilizer, i.e. the coefficients are not loaded correctly and the sound is therefore uneffected.

The rest of the configuration works, i can hear the correct sound.

If i let the same script run a second time then the coefficients are loaded and the sound is as expected.

is there any action i have to do to load and activate the coefficients?

i tried several ways:

single coefficient write, set of coefficient write (datasheet page 66).

with a logic analyzer i reconstructer the method from the APWorkbench and did the same with my controller.

first i noticed is that the order is other than that from the datasheet.

APWorkbench does the steps in the order

3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 2 - 18

this is writing the registers for the coefficients first and then the adress plus trigger.

the datasheet says first ram block, then adress, then coefficients and at the end the trigger.

i dont think this is crucial because every variant i tried results in the same behavior.

i dont get the coefficients into the ram at first try.

any idea on this?

#sta350bw-coefficient
1 REPLY 1
Nickname1623_O
Associate II
Posted on January 19, 2015 at 09:30

hi Harry,

according to your description , it seems that the coefficients had not been writen into register properly .

could you try to read out coefficients value after first time initialization ?

and due to coefficients writing will be synchronized with LRCK, could you check the I2S clock status , in case the clock is not stable , the coefficients writing result would be wrong.

Thanks