SigmaStudio Parameter Value Output bug

Because it's negtive, notice the highest Bit.

No, the 4 most significant bits sent out of the 32 bits are "no cares" because they don't exist in hardware. Therefore I see it as a bug when the output data makes any bits in this most significant nibble high; because they just don't exist and can not be high. See this thread for a similar complaint although it doesn't mention the output files specifically: https://ez.analog.com/message/33053#33053

Natan, you're correct, the top nibble is "don't care" because it doesn't exist in the hardware.

In fact, the most accurate way to display the data is neither

"0xFF, 0x81, 0xFE, 0xB0"

nor

"0x0F, 0x81, 0xFE, 0xB0"

but rather

"0xF81FEB0"

I'll check with the software team to see if they can modify the hex conversion method to leave the first nibble as zeros.

Actually, this is a bit of a tricky situation. CoolJavelin requested sign-extended data. Natan is requesting zero-padded data. Is there some kind of standard for this?

My concern is only related to the output data and how it is inconsistent with data read back from the chip. For example if you write the following parameter:

"0xFF, 0x81, 0xFE, 0xB0"

You will read back the following:

"0x0F, 0x81, 0xFE, 0xB0"

In my mind you should only write data to the chip what you expect to read back, excluding read only registers. Since with I2C you can not read or write in nibbles but in full bytes you can not have "0xF81FEB0" (although I do understand why this is more correct to the actual hardware).

I do not understand what CoolJavelin is saying exactly because I am only talking about output data and there is no Sign relevant data in the most significant nibble.

So the "0F....." , is correct to send to DSP.

When I using 5to23() function ,the results is "0F....".

But the sigma studio capture window is output "FF....".

So I modify 5to23() output as "FF...." when input is "-x.xx" to follow

The sigma studio output.

Is this way is right?

Sojourney,

If you are sending data to the SigmaDSP via I2C or SPI, you can send either 0Fxxxxxx or FFxxxxxx. The first 4 bits will be ignored, since they don't exist in hardware.