Sets the parameters for the Envelope Measure and Track function. This computes an 2**M length exponetial average of the N length block maximum of the magnitude of the high byte of the input samples. The parameters are packed as (M<<12)|N into a 16 bit register so the valid parameter ranges are (0<N<4096) and (0<M<16). The default is 0x4400, or M=4, N=1024.