static UINT16_T cn2, cn1, delta1;
static UINT16_T cn5,cn4,cn3, dn5, dn3, dn1,dn0

// lower half of figure 13, down sampled by 32
cn5 = cn4 - dn5;
cn4 = cn3 - dn3;
cn3 = dn0 - dn1;
dn0 = cn2;

// top half of figure 13 - operates a bit rate
M = 32;  // decimation ratio for a bis width of 16 bits
for(i=0; i<M; i++) {
  cn2 = cn2 + cn1;
  cn1 = cn1 + delta1;
  mout = get_next_bit();  // next ADS1106 bit from an imaginary FIFO
  delta1 = delta1 + (mout) ? 1 : 0;
  // delta1 = delta1 + (mout) ?1 : -1;  Or maybe this?
}

M = 32/4;  // processing 4 bits at a time
for(i=0; i<M; i++) {
  cn2 = cn2 + cn1;
  cn1 = cn1 + delta1;
  nibble = get_next_nibble();  // next 4 bits
  bitcount = _builtin_popcount(nibble);   // popcount returns the number of set bits
  delta1 = delta1 + bitcount;
}