Patent ID: 6462691
Filing Date: 2002-10-08
Classification: H03M

Abstract:
A method of scrambling successive, thermometer coded binary input data words having N bits into corresponding successive output data words also having N bits, the method comprising the steps of:maintaining certain bits of a binary value in positions of an output data word where a previous output data word had bits of the binary value; and randomizing a remaining number of bits of the binary value to positions in the output data word where the previous output data word had bits of another binary value to minimize the number of positions to be altered in a transition from the previous output data word to the output data word; wherein a switch net maintains the certain bits and randomizes the remaining number of bits of the binary value, the switch net including a plurality of switches, each switch being adapted to implement the Boolean equations: x=a*(b+not(cold))+b*cold; y=a*cold+b*not(cold); and c=p*c+p*not(a xor b)+c*(a xor b); where a and b are the inputs of the switch, x and y are the outputs of the switch, c is the actual state of the switch, cold is the previous switch state, and p is a random signal.