QUESTION FOUR (20 MARKS) a. Show the implementation of a 3-bit Johnson counter with SR flip flops and provide the state diagram (8marks) b. How does a Ring counter operate? Give a brief description of the counter implemented with 3 D (4marks) flip flop c. An 8-bit synchronous binary counter is initially loaded with the content 3A Hex. If the clock has a frequency of 1kHz, how soon is the first overflow registered? d. Convert the decimal number -100 into a sign magnitude format (6marks) (2marks)