We can use the ‘square’ function in MATLAB to generate a square wave. For more details on how to do so, please refer to the documentation of the same below-
We can then plot this generated wave using the ‘plot’ function, more details on the same can found below-
Next, to draw the cross-correlation, I am assuming that you aim to draw the cross-correlation of this square wave with itself. We can compute this using the ‘xcorr’ function in MATLAB. I have attached a code snippet below as a reference on how to do the same.
[crossCorr, lag] = xcorr(squareWave);
For more details on using the ‘xcorr’ function, please refer the below link-
Finally, we can plot ‘crossCor’ to visualize the results. I have attached screenshots of the of the square wave and its cross-correlation for further reference, below.