Available Components

Logicly offers a variety of logic gates, flip-flops, and other components for use in designing logic circuits.

Object Categories

The objects one may add to a circuit are divided into a few different categories, based on their function.

• Input Controls can pass a high (true) or low (false) signal to the circuit. Some, like the Toggle Switch, can change state with user input. Others, like the Clock, may change state based on time or another factor that is controlled by the simulation.
• Output Controls can be connected to an output pin to display its current state.
• Logic Gates perform boolean logic functions on the states of their input pins.
• Flip-Flops can store one bit of data.
• Other controls include various objects that do not fit into other categories.

More categories may be added in future versions of Logicly.

Object Types

The following objects may be added to a circuit.

• A Toggle Switch outputs a high (true) or low (false) signal (never high impedance (hi-Z) or error). It's state can be toggled by clicking the switch.
• A Push Button outputs a low (false) signal by default or a high (true) signal when it is pressed down.
• A Clock oscillates between a high (true) and low (false) signal over a set period of time, which may be configured. It's state is changed automatically by the simulation.
• A High Constant always outputs a high (true) signal.
• A Low Constant always outputs a low (false) signal.
• A Light Bulb displays the current state of an output pin using color.
• A 4-Bit Digit displays a hexadecimal digit (0x0-0xF) constructed from four inputs.
• A Buffer simply propagates the signal it receives. In the real world, a buffer will boost the electrical signal, if it has lost strength. In Logicly's simulation, one may use the buffer to affect propagation time.
• A NOT gate will change a high (true) signal to a low (false) signal, or it will change a low signal to a high signal.
• An AND gate will perform a boolean AND function on its input signals.
• A NAND gate will perform a boolean NAND function on its input signals.
• An OR gate will perform a boolean OR function on its input signals.
• A NOR gate will perform a boolean NOR function on its input signals.
• An XOR gate will perform a boolean XOR function on its input signals.
• An XNOR gate will perform a boolean XNOR function on its input signals.
• A Tri-State propagates the signal it receives, if it's enable input is high (true). If the enable input is in the low (false) state, it will output a high impedance (hi-Z) signal.
• An SR flip-flop is the simplest type of flip-flop. This master-slave implementation triggers on the negative edge of the clock input.
• A D flip-flop stores data on the positive-edge of the clock. It has asynchonous inputs for preset and clear that are inactive when the input signal is high (true). This implementation is based on IC 7474.
• A JK flip-flop is an improvement over the SR flip-flop because it is designed to avoid the race condition when both set and reset inputs are high (true). Like the D flip-flop above, this JK flip-flop is positive edge-triggered, and it has asynchonous inputs for preset and clear that are inactive when the input signal is high (true).
• A T flip-flop toggles its output when the T input is high (true). Like the D and JK flip-flops above, this T flip-flop is positive edge-triggered, and it has asynchonous inputs for preset and clear that are inactive when the input signal is high (true).
• A Bus allows you to combine multiple connections into a single connection. It is generally combined with tri-state buffers to output only one signal from its various inputs by ignoring any high impedance (hi-Z) signals. If the bus receives both high (true) and low (false) signals at the same time, it will output an error signal.
• A Pull Up will output a high (true) signal if its input is high impedance (hi-Z). All other input signals will be propgated without changes.
• A Pull Down will output a low (false) signal if its input is high impedance (hi-Z). All other input signals will be propgated without changes.

Additional object types may be added in future releases. For more information about the boolean functions performed by logic gates, please see Logic and Colors in Logicly for a truth table.

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