Class Notes (837,548)
Canada (510,312)
CSC258H1 (46)


2 Pages
Unlock Document

Computer Science
Steve Engels

SEQUENTIAL CIRCUIT DESIGN  Circuits using flip-flops  Example #1: Shift registers o A series of D flip-flops can store a multi-bit value (such as a 16-bit int) o Data can be shifted into this register 1 bit at a time, over 16 clock cycles o Implementing the register with these special D flip-flops will now maintain values in the register until overwritten by setting EN high  Example 3: Counters o Ex. 4-bit shift register used to store 1011 then 0000 o Consider the T flip-flop  Read from Q3 to Q0  Output is inverted when input T is high o What happens when a series of T flip-fliops are connected together in sequence o More interesting  Connect the output of one flip-flop to the clock input of the next  Example #2: Load registers o This is a 4-bit ripple counter o One can also load a register’s values all at once, by feeding signals to  Which is an example of an asynchronous circuit each flip-flop  Ex. a 4-bit load register  Timing isn’t quite synchronized with the rising clock pulse  Cheap to implement, but unreliable for timing o To control when this register is allowed to load its values, we introduce the D flip-flop with enable o This is a synchronous counter, with a slight delay o Truth table EN D 0 0 0 0 0 0 1 1  Could be synchronized even more by having each AND gate 0 1 0 0 combine outputs of all previous flip-flops 0 1
More Less

Related notes for CSC258H1

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.