to even computers are all based on sequential logic (its importance). Almost all digital circuits from traffic lights etc. It's my stand that just looking at the circuit diagram and replicating it on a bread-board is not what electronics is about.

When I say digital clock, you should expect something like the one in the picture! I wanted to try a different circuit for the same clock and I also chose it because it requires a lot of counters, and counters are based on sequential logic. But not all of us have the means to buy microprocessors or Arduino boards (as far as I am concerned they are expensive). So why have I chosen to implement that? Well usually clock circuits available on the internet (all circuits I have seen) use the 7490 counter (I have used 7493 but I will show why), microprocessors or Arduino boards. Digital clocks have been built by countless electronics hobbyists over the world. Virtually all circuits in practical digital devices are a mixture of combinational and sequential logic.This instructable is for two purposes 1) to understand and learn the fundamentals of sequential logic 2) use that knowledge to create a digital clock. Sequential logic is used to construct finite state machines, a basic building block in all digital circuitry, as well as memory circuits and other devices.

Or, in other words, sequential logic is combinational logic with memory. That is, sequential logic has state while combinational logic does not. This is in contrast to combinational logic, whose output is a function of only the present input. In digital circuit theory, sequential logic is a type of logic circuit whose output depends not only on the present value of its input signals but on the past history of its inputs.

In asynchronous circuits the state of the device can change at any time in response to changing inputs.įreebase Rate this definition: 0.0 / 0 votes In synchronous sequential circuits, the state of the device changes only at discrete times in response to a clock signal. When a 'channel up' or 'channel down' input is given to it, the sequential logic of the channel selection circuitry calculates the new channel from the input and the current channel.ĭigital sequential logic circuits are divided into synchronous and asynchronous types. The television stores the current channel as part of its state. In order for the channel selection to operate correctly, the television must be aware of which channel it is currently receiving, which was determined by past channel selections. However, if the television is on channel 8, pressing 'up' switches it to channel '9'. If the television is on channel 5, pressing 'up' switches it to receive channel 6. Pressing the 'up' button gives the television an input telling it to switch to the next channel above the one it is currently receiving. Virtually all circuits in practical digital devices are a mixture of combinational and sequential logic.Ī familiar example of a device with sequential logic is a television set with 'channel up' and 'channel down' buttons. Sequential logic is used to construct finite-state machines, a basic building block in all digital circuitry.

That is, sequential logic has state (memory) while combinational logic does not. In automata theory, sequential logic is a type of logic circuit whose output depends on the present value of its input signals and on the sequence of past inputs, the input history. Wikipedia Rate this definition: 0.0 / 0 votes

Sequential logic diagram