CSE260 Sequential Circuit Analysis Lecture 2

[00:00:06][Applause] [Applause] so yes Miss okay so at C buildups and truth table characteristic table excitation table problem circuit diagram to State diagram and state diagram to circuit diagram State diagram to circuit diagram are a type of problem is counter counter specific type of circuit let's get to the questions first but Di so imagine this is your question draw the state diagram for the given circuit you are given a circuit with flipflops flipflop the state diagram fop current state key next state key based on what inputs and outputs go so here you can see uh a sequential circuit using D FP flop so first what was the actual function it is something like present State key next state key a c b flip flop input key and flip flop output out [Applause] inputs and outputs so that's why we need the input Val one response how many flip flops are there in this circuit two H exactly fop fop we have two flip flops so plus next [Music] q+ A and A plus a fop B plus so we work this out if there are any external input soting are there any external input Namy it's also an input this is just clock input clock will always have a CL because this is C so we have three inputs D DB r x because it's only one external output output there is another output external it is not necessarily always there so now that I'm done with working out everything state in now to create State table I have to find out a function single a single so that's there were some other flip flop like fop a k a k s s a r a [Applause] s [Music] x a so it went through an end gate outut x h x a x BX BX a is the input of fop a X Plus BX now have to find out the correct values so D what's INB a a prime X now yes okay what equation for this X connected a prime AE so a plus a prime a plus a prime [Music] a b a b XE X Prime into a + b what do I have to do okay so AE y [Music] b have the state table truth table of the state diagram so first of all then a b r x present State and external input external input normally 0 1 0 1 2 3 4 5 6 7 b x like this a z but plus b one so one then DB equation AE X that means z y y so a a b into X halfway there we've worked out the inputs of the table and then we have we have worked out the value of the flipflop inputs and external output fops nextable you have to know this either you would work this out in the examination provided that you understand this car D value a plus next next sorry a present State B so J Miss okay so what do I have here the inputs first of all now that done cating all thisable a possible combination St Z State F fler State one combination fop State one second flip flop state zero combination one Z fop State one one state state state state one one state one St are external inputs and outputs for which input and output so first State one state one Zer state or one one state each state what input and output so State 0 so y Val had there been no y just and output because input one output Z while external input is one and output is zero 01 01 while X is and Y is 1 so 0 1 while external input is z and external output is one y one and Y 1 1 X1 y so 1 1 X1 y y1 y11 yes ma'am and after a number of steps we have present State key next state key input of the flipflops extern outut external input fop you don't have to do that you're going to write this table [Music] andn possible State 0 0 1 1 0 1 1 possible question yes ma'am so there is another example draw the state diagram for the given circuit f input possible external plus are input j a k a JB KB r x so d a DB r y j b directly b j a equal to B now then k a equal to ke Ka a so BX X Prime JB [Music] [Music] J exerted act input x a X or [Applause] xation straight table okay so a b x in variable combin so B x z and one and and have to know this a a a Z so next Zer Val same 0 0 Pres [Music] one memory memory yes' previous question can state1 1 external 01 while external question soop FP flop carries any specific significance first diagram as follows get the sequential circuit using JK f fop inform flip flop fop external present State 0 external input one next 01 if this feels next1 then external input keate input fation table so flip flop next state a state Z next St Z don't Z State Z next one one don't care State one next state one B plus that means state next station table draw the [Music] circuit [Music] easier so [Music] F external inp [Music] variable a b x now that you have found out the equations b b x Prime k a b x JB X or KB a or a X not X next state key external input now that you have find that found [Music] out us so question yes missign using flip flop circuit is based on state table below you already have the table have okay how to draw the state diagram from a circuit diagram or how to draw a circuit from a state diagram State table okay circuit that is created using flipflops counters or circuits that cycle through a specific specified number of states 0 1 2 3 there are two types of counter synchronous and asynchronous synchronous and asynchronous synchronous and asynchronous key synchron have to what counter isign using theen logic design process this is your question design a two bit synchronous binary counter possible possible 0 0 1 1 0 1 one fops fop with identical J inputs fop withp it just meanit synchron using F flops 0 0 then Arrow 0 1 0 1 AR 1 1 Z Arrow 1 a St T FP flop input Z State Z One fop one present State one and next state one input Zer and present State one and next Z input one ta1 f up either we can use or you can t a A1 prime a plus A1 a t AAL either you use albra or you use or anything else up to bit synchronous binary counter using T flipflop 3 bit synchronous binary counter value 1 1 2 1 1 1 1 1 1 0 111 bit synchronous counter flip flop flip flop fop plus a 1 plus a not Plus 1 1 a A1 either or use count problem yes up down synchronous counter that [Music] means 2 1 1 up down Di [Music] at a time up or down [Music] but there will be a switching State first of allit synchronus up down counter2 q1 q and Q2 plus q1 plus Q Q2 q1 down 1 one1 that means 0 0 1 one 1 1 1 1 1 0 so ult down count 0 7 7 6 5 5 4 four three 3 2 2 1 one zero 1 3 2 Four 3 2 3 4 5 6 down Q2 Q2 plus2 q1 and q1 Q q1 startable Vari lb M Q2 q1 Q M2 q1 Q yes up down counter normal counter the directly synchronous 3it counter but two bit counter considering all the values there are 0 1 1 2 2 3 3 4 4 5 5 6 6 s implement the following counter using t flipflop c 2 3 3 Take 5 5 7 7 11 11 13 13 one fop 1 1 1 1 1 11 which is 1 1 1 11 1 so 13 one 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 this is your initial state either res 0 1 0 for next dat Z ini 1 so that's [Music] why which is one 6 8 9 10 12 14 15 1op A2 A1 a yes Miss so what you can do is you will go through all of you 2 3 green yellow red yellow green so this is not value 1 1 1 1 one yell exteral ellell then 1 1 yellow so 1 0 1 1 0 1 GRE yellow 01 red 1 that's why it ised as don't care so supposed to work this out yourself practice Mak Ma'am why is this I only want to know why is this like last sem online pretty so I don't no teacher enjoys this I promise you you participate makes us feel better for I'm just providing so make sure you understand this this is very important flipflop question comparatively f important so make sure you understand [Applause] this so