14. An apparatus according to claim 13, wherein the offset factor `b` is an offset relative to the most significant bit of a first byte within the first data word, and an output data byte y[7 . . . 0] is generated according to the following rules: for 1-bit data objects: y[i]=x[7-b] for 2-bit data objects: y[i]=x[7-b] for i=1,3,5,7 y[i]=x[6-b] for i=0,2,4,6 for 4-bit data objects: y[3]=x[7-b] y[2]=x[6-b] y[1]=x[5-b] y[0]=x[4-b] y[7]=x[3] y[6]=x[2] y[5]=x[1] y [4]=x[0] for 8-bit data objects: y[i]=x[i] for 16-bit data objects: y[7 . . . 0]=x[15 . . . 8]
13. An apparatus according to claim 7, wherein, if an input data word comprises packed data objects which are less than 8 bits wide, the programming agent provides an offset factor `b` to the control unit, which in turn selects which bit in the first data word is used as a starting bit for normalisation by the normalisation circuit.