TAS3308 mute problem

Jes,

   It would be helpful to know your hardware platform that you are working with. Are you using the TAS3308EVM?

Also from your comments on the mute control bits it would appear to indicate that you are trying to mute the DIT. Is this correct? If not, what are your trying to mute.

Also - please provide a register dump of the Mute Control register so I can understand your set up in detail.

Mosgaard said:

The mute control register documentation is not very good - it doesn't contain any information on where the mute control bits are in the 4 bytes the register consist of :-)

   Could you be a little more specific in regards to exactly what type of description you are looking for? This will help us provide the correct documention.

Hi Drew,

I am using our own developed platform where an external microcontroller is controlling the mut pin as input to the TAS3308. I don't have access to reading the mute control register, but it is unchanged from default content after boot.

I would like to mute the TAS when updating filter coefficients over I2C from the micro during runtime,

best regards

Jes

Jes,

    You should be able to read the contents of the mute register via I2C to verify that it is behaving as intended.

Hi Drew,

OK if that is the only thing to do now we will implement a "read 4 bytes from an i2c adress" for the micro so we can get the information back through our PC command interface. But what should we look for, if you look at the table 14.5 in the manual on page 90 there is nothing related to mute control mute(1:0) are they hidden in the upper 2½ bytes which is marked as unused?

Best regards
Jes

Hi Drew,

I have read the register 0x09 and the result back from it is 0x00 0x00 0x00 0xFF

best regards

Jes

Hi Drew,

I finally got it now I think - the mute(1) and mute(0) mentioned on page 90 is not signals in the register but just a way of showing e.g. PWM1(D7) and PWM1(D6) and their related possible states - right? so if I read back all ones from D7 to D0 it means that the output control is in the force mute off mode.

The next question is then how it got into that mode, it should default to all zeros in the register and I am pretty sure that we are not writing to the address 0x09 from the micro controller so do you have any idea how it got into that mode?

best regards
Jes

Jes,

     Your understanding is correct. If you simply write the desired 4 bytes back to the register the mute pin should work.

Hi Drew,

correct I have tried that already and the mute pin works - but my next problem is then where does the FF's come from in the last byte? I do not write anything to that register from the micro host processor, but I can't control what is in the hex file from the GDE application where I do the development - do you have any idea if it could be included in that during the TAS3308 boot process or where else ?

best regards
Jes

Jes, have a look in your process flow and search for 'Init3308_1', if it not there insert it from the 'initialisation' components. It has all the properties you are looking for...

Regards

Neil

www.milton-electronics.com

Jes,

    Neil's suggestion should work beatuifully here.

One reason it may be FF's is probably a change in the TAS boot code. The Datasheet outlines the default operation of the device itself.   In other words, the default ROM code defaults to force the mute off.

    When you load a program via PurePath Studio image, you are actually opertating the device out of RAM, therefore the code generated via PPS is probalby setting the register LSB to 0xFF. With the Initialization file included in to the program, it will generate an image with the mute pin working as expected without the need for an additional write to the mute register.