Preload value of IIR filter?

I'm working on making thermal models of speaker drivers to guard these from overheating, and predict before they overheat. I made a model for the power delivered to the driver and are modelling voice-coil and motor structure as two IIR filters with time constants for voice-coil Tvc and motor Tm. At startup and after I detect only low power has been delivered to the speaker for a while, more than 5xTvc, I want to re-calibrate the model by a reading of the actual voice-coil temperature witch I can measure through its impedance. To do the re-calibrate I need to insert values into the IIR registers. Can I do this somehow?

If I cannot load the IIR registers with a value, can I then change the coefficients to a quick settling time, input my calibration value, and change back to long settling time coefficients. Will the registers retain their values after I update the coefficients?

Cheers,

Thomas *<:-D

filter

sigmastudio

iir