Patent ID: 6903663

Claim:
A method of converting a number (r) into a signed binary representation in m+1 digits (r′ m , . . . , r′ 0 ) from its binary representation in m bits (r m−1 , . . . , r 0 ), comprising the steps of: a) adding a bit (r m ) of rank m, a bit (r −1 ) of rank −1 and a bit (r −2 ) of rank −2 to the binary representation of the number (r), and initializing said added bits to a value of 0, b) providing at least one calculation variable (b), c) initialising to the value 0 a bit of rank m (b m ) of said variable, and d) performing a conversion loop, for i equals m to 0, comprising the following operations: (1) applying as inputs (e 1 , e 2 , e 3 ) of a first calculation means the bit of rank i (b i ) of the calculation variable (b), and the bits of ranks i−1 and i−2 (r i−l , r i−2 ) of the binary representation of the number to be converted, said first calculation means performing an arithmetic sum of the bits applied as inputs (e 1 , e 2 , e 3 ) and dividing said sum by two, to supply as an output the bit of rank i−1(b i−1 ) of the calculation variable (b), (2) applying as inputs (e 1 ′, e 2 ′, e 3 ′) of a second calculation means, the bits (b i , b i−1 ) of rank i and i−1 of the calculation variable (b), and the bit (r i ) of rank i of the binary representation of the number to be converted (r), said second calculation means performing an arithmetic operation equivalent to the multiplication by minus two of the bit of rank i of the calculation variable (b), and the arithmetic sum of said multiplication with the other two bits applied as an input, in order to supply as an output the digit of rank i (r′ i ) of the signed binary representation.