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ITEC 352. Lecture 9 Flip Flops. Review. Questions? HW #2 posted, due next Friday at 10PM Floating point numbers. Outline. Rationale SR D T JK. Gates. So far what have we seen circuitry wise? What can we do with what we have learned? What can’t we do?. Idea.
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ITEC 352 Lecture 9 Flip Flops
Review • Questions? • HW #2 posted, due next Friday at 10PM • Floating point numbers
Outline • Rationale • SR • D • T • JK
Gates • So far what have we seen circuitry wise? • What can we do with what we have learned? • What can’t we do?
Idea • Have the output tied to the input
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
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?
Gating the gates • What does this image bring to mind?
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
D Latch • Adding the 1/1 combination • Just like an SR latch except it handles the 1 1 input condition gracefully
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
T Flip/flop • Toggles value when T is 1 • Clock pulse changes values
JK Flip/Flop • Universal flip/flop • J=set, K=reset • 0 0 is hold • 1 1 is toggle
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?
Summary • Flip flops • Latches • Storing bits