ITEC 352 Lecture 9 Flip Flops. Flip flops Review Questions? HW #2 posted, due next Friday at 10PM...
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Transcript of ITEC 352 Lecture 9 Flip Flops. Flip flops Review Questions? HW #2 posted, due next Friday at 10PM...
ITEC 352
Lecture 9Flip Flops
Flip flops
Review
• Questions?• HW #2 posted, due next Friday at
10PM• Floating point numbers
Flip flops
Outline
• Rationale• SR• D• T• JK
Flip flops
Gates
• So far what have we seen circuitry wise?
• What can we do with what we have learned?
• What can’t we do?
Flip flops
Idea
• Have the output tied to the input
Flip flops
Why?
• State–Why is the state of a machine
important?– How does this relate to programming?–What does hooking up the output to the
input do to our idea of timing?
• Not a new idea– Back in 1918
Flip flops
SR
• Set and reset latch– Can be implemented with NAND gates
What is the truth table for this set of gates?What input set should we stay away from?
Flip flops
Gating the gates
• What does this image bring to mind?
Flip flops
Issue
• Changes in the input immediately change the output
• Sometimes keeping the state the same even though the input changes is required
What is the truth table?What do you think E does
Flip flops
D Latch
• Adding the 1/1 combination– Just like an SR latch except it handles
the 1 1 input condition gracefully
Flip flops
Clock cycles
• Some sort of order needed– Conductor in an orchestra
• Need to preserve values through each “beat”
• Behavior– Designed to delay the output by 1 cycle– Allows access to previous cycles result
Clock pulse
Flip flops
T Flip/flop
• Toggles value when T is 1• Clock pulse changes values
Flip flops
JK Flip/Flop
• Universal flip/flop• J=set, K=reset• 0 0 is hold• 1 1 is toggle
Flip flops
Next steps
• Have the capability to store information
• Have the capability to manipulate binary bits for mathematical and boolean tasks
• How does it all fit together to form a computer?
Flip flops
Summary
• Flip flops• Latches• Storing bits