Quantisation using matlab simulink

I am new to simulink. I need 1 bit quantiser (ie 2 levels) , 2 bit quantiser (ie 4 levels), 3 bit quantiser (ie 8 levels) etc.. How can I set the parameters in the quantiser block in simulink to model these requirements. Because it only has the quantiser interval to specify (by default it is 0.5). Should I use a different model or approach?