Block Diagonal Matrix

I have a problem in transforming a matrix to block diagonal matrix. My matrix is like:

\begin{array}{cccc} a & b & c & 0 \ b & 0 & 0 & c \ c & 0 & 0 & b \ 0 & c & b & a \ \end{array}

I want to make a block diagonal matrix by using Kronecker product and the other process related matrices.

\begin{array}{cc} A & 0 \ 0 & B \ \end{array}

where A and B are the 2*2 matrices.

Thanks