SDS homework

Consider the SDS where each function is XOR over {0,1} and the graph is the following.
1--3--2--4--0 (Where the vertices are the numbers, the edges are the dashes, and the update order is denoted by the value of the numbers.)

Draw the state transition graph (which will show us the phase space) of this SDS.
Give a two-dimensional cellular automaton that simulates this SDS. You may use a function different from XOR, a larger function space than {0,1}, and/or even more than 4 cells, but your cellular automaton must have the property that for every n rounds of running there is a subset of the nodes in the cellular automaton that are the same as the nodes of the SDS after running one round. You may also have the cellular automaton wrap around from top to bottom or left to right.