Nptel video lectures, iit video lectures online, nptel youtube lectures, free video. Different types of sequential circuits basics and truth table. Srinivasan, department of electrical engineering, iit madras for more details on nptel. Dec 17, 2007 40 videos play all electronics digital circuits and systems nptelhrd marty lobdell study less study smart duration. This channel contains technical lectures on electronics and communication engineering from seven indian institutes of technology iits and indian institut. Types of sequential circuits there are two types of sequential circuit. Easy to build using jk flipflops use the jk 11 to toggle. Sequential circuits can be categorized as being synchronous or asynchronous.
In sequential circuits, the \state of the circuit is crucial in determining the output values. There is no signficance to the fact that the number of. Binary counters simple design b bits can count from 0 to 2b. Nptel provides elearning through online web and video courses various streams. Structural design of sequential circuits a sequential circuit follows the general model shown below. Sequential circuits cmos vlsi design slide 8 typical layout densities qtypical numbers of highquality layout qderate by 2 for class projects to allow routing and some sloppy layout. It is the basic storage element in sequential logic. Srinivasan, dept of electrical engineering, iit madras. Sequential logic sequential circuits simple circuits with feedback latches edgetriggered flipflops timing methodologies cascading flipflops for proper operation clock skew asynchronous inputs metastability and synchronization basic registers shift registers simple counters hardware description languages and sequential logic. Digital circuits and systems dvd media storage type. Basically, sequential circuits have memory and combinational circuits do not. Sequential circuits 1 rs latch d latch flipflops d registers january 25, 2016. Sequential circuits until now, circuits were combinational when inputs change, the outputs change after a while time logic delay thru circuit combinational circuit inputs outputs we want the clock to act like a start and stop signal a latch is a storage device that stores its inputs at a rising clock edge and.
Where 00 a, 01 b, 10 c, 11 d derive the state diagram from the state table. A sequential circuit is a combination of combinational circuit and a storage element. This type of circuits uses previous input, output, clock and a memory element. Your browser does not currently recognize any of the video formats available. The fundamental principles of sequential logic show us how to construct circuits that switch from one operating point to the other. Digital electronics part i combinational and sequential logic. For a given input combination, a sequential circuit may produce different.
Output is a function of both the present state and the input. Digital circuits and systems nptel online videos, courses iit. These circuits almost never have instability problems. The state register is controlled directly by an external clock and reset signal. Digital circuits and systems online course video lectures. Elec 326 19 sequential circuit analysis derive the state table from the transition table. Asynchronous sequential circuit these circuit do not use a clock signal but uses the pulses of the inputs. Storage elements memory used in clocked sequential circuits are called flipflops. A sequential circuit is a logical circuit, where the output depends on the present value of the input signal as well as the sequence of past inputs. Sequential circuits a sequential circuit consists of a combinational circuit and a feedback through the storage elements in the circuit. Combinational logic a combinational system device is a digital system in which the value of the output at any instant depends only on the value of the input at that same instant and not on previous values. A synchronous sequential circuit usually has a clock pulse clocked sequential circuits.
For example, let us talk about sr latch and sr flipflops. These circuits are faster than synchronous sequential circuits because there is clock pulse and change their state immediately when there is a change in the. Lecture 12 modeling of verilog sequential circuits core statements continued. Register array in mips, there are 32 registers, and each is 32 bits. A sequential circuit combinational logic circuit that consists of inputs variable x, logic gates computational circuit, and output variable z combinational circuit produces an output based on input variable only, but sequential circuit produces an output based on current input and previous input variables. A sequential logic circuit typically has some type of memory element to hold the state of the circuit. Different models, simulation cycles, process, concurrent and sequential. Srinivasan department of electrical engineering, iit madras. Autumn 2003 cse370 vi sequentai llogci 1 sequential logic sequential circuits simple circuits with feedback latches edgetriggered flipflops timing methodologies cascading flipflops for proper operation clock skew asynchronous inputs metastability and synchronization basic registers shift registers simple counters hardware description languages and sequential logic. But sequential circuit has memory so output can vary based on input. Oct 26, 2012 sequential circuits outputs depend on present inputs and previous inputs also it contains memory elements for storing previous state inputs examples of sequential circuits are flip flops, counters, shift registers 4. Switching circuits and logic design usb media storage type.
Sequential circuit analysis university of pittsburgh. While a combinational circuit is a function of present input only. Now, this is much like what we discussed in combinational logic. Vlsi design low power memory circuits exam study material for. Lecture 5 synchronous sequential logic linkedin slideshare. Block diagram flip flop flip flop is a sequential circuit which generally samples its inputs and changes its outputs only at. Digital electronics part i combinational and sequential. Jan 12, 2019 in this tutorial, we will learn about sequential circuits, what is sequential logic, how are sequential circuits different from combinational circuits, different types of sequential circuits, a few important sequential circuits basics and many more. Nptel provides elearning through online web and video courses various. Lecture 11 modeling of verilog sequential circuits.
Lecture computing 17 design verification and test of. Lecture 24 design of synchronous sequential circuits. Dec 17, 2007 autoplay when autoplay is enabled, a suggested video will automatically play next. Autoplay when autoplay is enabled, a suggested video will automatically play next.
Definition of state machines, state machine as a sequential controller. Read the full comparison of flip flop vs latch here. Nptel video lectures, iit video lectures online, nptel. Sample of the study material part of chapter 5 combinational. A sequential logic circuit typically has some type of memory element to. Nptel video lectures, iit video lectures online, nptel youtube lectures.
Sequential circuits the digital circuits we have seen so far gates, multiplexer, demultiplexer, encoders, decoders are combinatorial in nature, i. Arithmetic with number systems, signed and unsigned number systems and their arithmetic. Digital circuits and systems online course video lectures by. Ripple counter increased delay as in ripplecarry adders delay proportional to the number of bits. Up next lecture2introduction to digital circuits duration. Vlsi design low power memory circuits exam study material. Nptel syllabus digital system design with plds and fpgas video course course outline design. Hierarchy, controller fsm, case study, metastability, synchronization, fsm issues, timing issues, pipelining, resource sharing. Lecture 12 modeling of verilog sequential circuitscontd. Combinational logic and sequential logic are the building blocks of digital system design. Clocked sequential circuits used to control storage elements are the most common types used. Sequential logic digital video lecture all about circuits. The basic difference between a latch and a flipflop is a gating or clocking mechanism. Verilog coding, metal oxide seminconductor field effect transistor mosfet, fabrication process and layout design rules, propagation delays in mos, power disipation in cmos circuits, semiconductor memories.
Prerequisites basic knowledge of electronics and electrical circuits. Sequential circuits slide 8cmos vlsi design typical layout densities typical numbers of highquality layout derate by 2 for class projects to allow routing and some sloppy layout. Here is a sequential logic circuit and this is just an example. Different types of sequential circuits basics and truth. Designing sequential logic circuits implementation techniques for flipflops, latches, oscillators, pulse generators, n and schmitt triggers n static versus dynamic realization choosing clocking strategies 7. Q x0 x1 aa b0 bb d0 cc a1 dd c1 q z elec 326 20 sequential circuit analysis 4. Lecture computing 17 design verification and test of digital vlsi circuits nptel video course modulex lecturei atpg for synchronous sequential. That means sequential circuits include memory elements. Lecture 16 introduction to sequential circuits youtube.
Consist of a combinational circuit to which storage elements are connected to form a feedback path. Introduce several structural and behavioral models for synchronous sequential circuits. Flip flop is a sequential circuit which generally samples its inputs and changes its outputs only at particular instants of time and not continuously. Click here to visit our frequently asked questions about html5 video. Give a precise definition of synchronous sequential circuits. Next states and outputs are functions of inputs and present states of storage elements 54 two types of sequential circuits. Digital electronics state assignment exam study material. Modeling of verilog sequential circuits contd lecture rtl coding guidelines. Later, we will study circuits having a stored internal state, i. Gate preparation, nptel video lecture dvd, electronicsandcommunicationengineering, vlsidesign, lowpowermemorycircuits, nmos transistors, pmos transistors, mos process parameters, cmos process parameters, cmos electrical properties, cmos device modeling, scaling principles, fundamental limits, cmos inverter scaling, cmos propagation delays.
Sequential circuits outputs depend on present inputs and previous inputs also it contains memory elements for storing previous state inputs examples of sequential circuits are flip flops, counters, shift registers 4. Lecture 12 modeling of verilog sequential circuits. A sequential logic circuit can have any number of inputs and any number of outputs. We now consider the analysis and design of sequential circuits. Digital electronics state assignment exam study material for. Consequently the output is solely a function of the current inputs. All sequential circuits contain combinational logic in addition to the memory elements. Digital vlsi system design nptel online videos, courses.440 1265 48 1272 463 645 1406 720 244 1502 1182 1439 1372 1036 544 1030 214 746 1557 921 786 388 590 618 746 917 1013 1322 1453 180 17 316 633 1304 592 762 1355 358