Adders and flip flops(1.4.3 e) Flashcards
Adding
have two input bits A&B
have two output bits sum and carry
sum = A⊽B
carry = A∧B
The half adder
takes two input bits(A, B) and computes the sum with the two output bits(sum and carry)
Full adder
Combining full adders
each full adder is responsible for each pair of bits any carriers are passed to the next full adder
What is a flip flop?
a device which switched between two outputs based on the combination of two inputs
What is one input in flip flops?
one is the data signal which will be a stream of information that switches between 1 and 0 depending on the data being sent
What is the second input in flip flops
the other is the clock which triggers a read of the data stream at regular pulses
What are outputs usually denoted as in flip flops?
Q and ¬Q
D-type flip flop
relatively easy to understand job: change the output to whatever the input is at each clock pulse
What is the edge of the signal?
the exact moment of the switch
What is a rising edge?
when the clock switches from 0 to 1
What is a falling edge?
when the clock switches from 1 to 0
What is the period of the clock?
the time between successsive
What is rising edge triggering?
the output of the D-type flip flop is decided on the rising edge of the clock
Edge triggering
if the data input is at 1 at the rising edge of the clock then the output will be Q
if the data input is at 0 at the rising edge of the clock then the output will be ¬Q
