Need help with weird circuit design truth table (1 Viewer)

[mAtboisLim]

Question 25 (c) (i) of the 2001 CSSA Trial exam has a really strange flip flop circuit design. It requires you to draw a truth table for the circuit they give you. Can anyone someone please explain how you get the answer they give you in the solutions.

http://www.boredofstudies.org/courses/techsci/sdd/CSSA_SDD_2001_sol.zip

 

[mlando]

they are missing half of the truth table. you would do the question as follows:

first suppose that Q=0, Q'=1. this tells you one of the inputs to each of the AND and NOR gates. now suppose A=0 and B=0. then we get that C=A AND Q=0, D=B AND Q'=0. now suppose that A=1,B=0 then do the same as above. repeat for A=0,B=1 and then for A=1,B=1.

then suppose that Q=1 and Q'=0 and repeat for each of the four possible combinations of values for A and B.