Incorrect non restoring division for unsigned integers !!

Hi there,

For unsigned integer values, I am attempting to construct a non-restoring division algorithm, but it appears that I am having difficulties getting the quotient and remainder right.

Can you give me some advice on how to improve the implementation?

Many thanks

clearvars;clc;
n = 32;
N = 11;
D = 3;
R = zeros(1,1);
Q = 0;
D = bitshift(D, 1); 
for i =  1 : (n-1) %.. 0 do  -- for example 31..0 for 32 bits
    if R >= 0 
        Q = accumpos(Q,1);
        R = 2 * R - D;
    else
        Q = accumneg(Q,1);
        R = 2 * R + D;
    end 
end
Q = Q - not(Q); %      -- Appropriate if −1 digits in Q are represented as zeros as is common.
if R < 0 
  Q = accumneg(Q,1);
  R = R + D;  %-- Needed only if the remainder is of interest.
end
Q ,R

Q = -30

R = 0