Workbench Tools

Component creation & modification

Component creation

On the left side is the component menu. If you click on a component button and release, you can thereafter create components of this kind, as many as desired, by clicking on the design area. If you click on a component button and release on the design area, then a component of this kind is created and the mode immediately changed to the wiring mode.

The component buttons have small triangular corners. With these you get into the menus of the respective components.

Below is a list of options:

  • Text: You can select italic writing, bold print, over and underlining, Sub and Superscripts as well as character size. With Sub and Superscripts the text is only single-line. Text can be used to assign labels for signal sources (Button, Calliper, oscillator) and signal sinks (lamp and Seven segment display). For this you click the Text button, and then move or click on the appropriate component. The relevant text will then follow the component if it is moved. Labels are always single line.
  • Button: Here you can select the normal button (rocker switch), the Calliper (push-button), the oscillator and the constant signal sources HI (1) and LO (0). In addition, you can enter the size of this component.
  • Lamp: You can select the seven segment display (7-Seg) and the seven segment display with an integrated 4-Bit hexadecimal decoder (7-Hex) in remplacement of the lamp. In addition, you can choose the size of this component.
  • And/Or: You can select the number of entrances as well as the NAND and NOR variant.
  • Xor: The Xnor is also selectable here.
  • Thresh: The Threshold gates are gates that output a one only when there is at least as many inputs set to one as the threshold. The Threshhold State gates maintain a one level until against all entrances are set to 0 again. Logically the threshold value cannot exceed the number of inputs.
  • Adder: This is the adder selection menu. You can select between the half and adders and the Carry Lookahead adder.
  • Mux: Here multiplexers and Demultiplexer are selectable. With the multiplexer the number of entrances is selectable, with the Demultiplexer the amount of of exits as well as the value, which the not selected exits are to accept.
  • RS-FF: This is the flip-flop selection menu. One can select between R-S, JK, D and T-flip-flop, and in case of a flip-flop still another Clock, clock edge control or the master Slave variant. If one or more of these three variants is mandatory, they will be automatically selected. Additionally, except with the simple R-S flip-flop, you can add asynchronous SET and RESET inputs.
  • Register: Here there is a shift register and a counter: they are both adjustable, like how many FlipFlops exist, or whether they are Master Slave FlipFlops. The remainder input (R) is however never affected!
  • Delay: Here you can select between an ideal delay, a slow-acting delay (absorb). If you additionally selects "two way", then there is a delay time for the change from 0 to 1 (left edge), and one for the change from 1 to 0 (right edge). These delay times are directly adjustable on the component by typing the values.
  • Misc: You will find here:
    • the inverter
    • Logic Analyzer: This is like a digital oscilloscope and can be used as an ordinary signal sink. For this there are connections on the left that you can use to link to the circuit. In addition, the oscilloscope can be used as analysis aids. For this, there is on the right of each oscilloscope channel a numeric point, , which can be drawn on any wire in the circuit. You can push the measuring point anywhere on the circuit, the measuring point and the appropriate token on the oscilloscope become green, and the signal, which the appropriate wire transfers, is sent to the appropriate channel of the oscilloscope. The oscilloscope has different adjustment possibilities:
      • ON/OFF: Switching on and off.
      • GRID: To indicating vertical lines with a distance from a time step, in order to be able to compare the signals easely.
      • CLEAR: To clear the oscilloscope display.
      • SIZE: Similar to the other signal drains (and sources): you can increase the oscilloscope size, however only on the oscilloscope and not in the selection menu. You can change the sizes only if all measuring points at the equipment are unaffected, otherwise this button disappears from the oscilloscope display.
      • CHANNELS: To adding or removing from channels. Up to 16 channels are possible.
      • SCROLL: This Slider appears only if either the simulation or the oscilloscope are switched off. Then you can see the received signals of the last 200 time steps.
      • SCALE: Here you can change the Y-scaling of the oscilloscope display.
  • Custom: Here you can select own components, if you already have created such

While a menu is open, you can click on the design area to create a new component. Clicking on a button in the menu selection and dragging in the design area creates also a new component, and causes thereafter immediate changing into the wiring mode.

You find a demonstration of all components here.

Component modification

In the modification mode, you can change the type of certain components.

For this, after selecting the modification button from the component menu, select a new component exactly the same way as when adding new components. Then, click (or drag) on an already existing component. The new component will replace the previous one, and even already connected wires to the inputs and outputs will stay attached to the component (if possible).

You can replace a component only by similar component, thus for instance an AND gate by an OR gate (or also a flip-flop), or a lamp by a seven segment display, but e.g. not button by a half-adder.



LogiFlash, Original Text and Example:
Technische Informatik Universität Frankfurt