My customer uses the ADAU1452->level detectors/lookup tables->level detectors->multiple bands->Pass Thru RTA or RTA to Output algorithms that available in sigmastudio to measure the signal level. When the 0dB signal is input, the sigmaStudio and USBi emulator get the value of the "_RTA_OUT_0" register as (0x1D,0xBA,0xxx,0xxx), according to 8.24 format conversion this meas 29.xxxxx, which obviously cannot be converted to the correct 0dB value. (If use single band->running average->single level detector, the output can be converted to the correct db value)
If read the register values of "biquad3LevelDetGrowS3001_rmshi_0" and "biquad3LevelDetGrowS3001_rmslo_0" and form a double-precision(56bits) number, this method calculates the same dB value as whitch displayed on the sigmastudio GUI.
However, we observed through oscilloscope that USBi could only obtain the value of "_RTA_OUT_0" register to convert it into dB value, but did not read the values of the above two registers. So how does SigmaStudio convert the value of the ADAU1452 "_RTA_OUT_0" register into the right dB value?