DOCS.md

LogicRs Documentation

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0. Contents

• 0. Contents
• 1. Application Overview
  • Saving and Loading Projects
  • Editor Controls
  • Keyboard Shortcuts
• 2. Builtin Modules
  • Basic Modules
  • Input/Output Modules
  • Gate Modules
  • Combinational Modules
  • Latch Modules
  • Flip Flops
• 3. Custom Modules
  • Creating a new module
  • Exporting Modules

1. Application Overview

When you first start up LogicRs, you're greeted with an empty project file. The presented window will look something like this:

Here you can start by selecting a module from the module list on the left side and placing it in the editor area with a left click.

You can connect two blocks together by dragging from the output connection of one block to an input connection of the other block.

Note Feel free to look into the examples directory for example projects.

You can search for modules in the side bar by clicking the magnifying glass icon on the top left.

Saving and Loading Projects

Projects can be loaded using the "Open" menu item in the main menu (top right).

Projects can be saved using ctrl + S or the "Save" menu item in the main menu.

The file format used for LogicRs projects is .lrsproj.

Editor Controls

• right click: (selection) context menu
• left click: (un-)select or interact with a block
• mouse drag:
  • in empty space: select all items in an area
  • on a block: move that block
  • on a waypoint: move that waypoint
  • on an output connector: draw a new connection between two blocks
  • with alt: draw a new connection from a waypoint
  • with ctrl: move the editor view
• mouse wheel: zoom in or out of the editor

Keyboard Shortcuts

• ctrl + A: select all items in the current editor
• ctrl + C: copy the current selection
• ctrl + X: cut the current selection
• ctrl + V: paste the currently copied items
• ctrl + Z: undo last action
• ctrl + Y: redo last action
• ctrl + Q: quit the application
• ctrl + ,: show about screen
• ctrl + S: save the current file
• ctrl + shift + S: save the current file as...
• ctrl + O: open a file
• ctrl + N, ctrl + W: create a new project
• del: delete the current selection
• ctrl + shift + N: create a new module
• ctrl + F: search for a module

2. Builtin Modules

LogicRs features several builtin modules available for every project. Here is a list of all modules built-in by default:

Basic Modules

• High: outputs a constant 1 signal
• Low: outputs a constant 0 signal

Input/Output Modules

• Button: momentary push-button reacting to user input

  

• Lamp: lights up when the input signal is 1

  

• Switch: toggle button reacting to user input

  

Gate Modules

• And: outputs 1, when all input signal are 1:

  

  A	B	Output
  0	0	0
  0	1	0
  1	0	0
  1	1	1

• Nand: inverse of And:

  

  A	B	Output
  0	0	1
  0	1	1
  1	0	1
  1	1	0

• Nor: inverse of Or:

  

  A	B	Output
  0	0	1
  0	1	0
  1	0	0
  1	1	0

• Not: outputs the inverse of the input signal:

  

  Input	Output
  0	1
  1	0

• Or: outputs 1 if either A or B or both inputs are 1:

  

  A	B	Output
  0	0	0
  0	1	1
  1	0	1
  1	1	1

• Xnor: inverse of Xor:

  

  A	B	Output
  0	0	1
  0	1	0
  1	0	0
  1	1	1

• Xor: outputs 1 if either the A or (strictly) B input is 1:

  

  A	B	Output
  0	0	0
  0	1	1
  1	0	1
  1	1	0

Combinational Modules

• Mux: A 2:1 multiplexer, selecting either the A or B input based on the S input:

  

  S	Output
  0	A
  1	B

• Demux: A 1:2 demultiplexer, selecting either the O0 or O1 output based on the S input:

  

  S	O1	O0
  0	0	A
  1	A	0

Latch Modules

• JK Latch: Latch similar to the SR Latch, but toggeling its value when both inputs A and B are 1:

  

  A	B	Action
  0	0	No change
  0	1	Reset
  1	0	Set
  1	1	Toggle

• SR Latch: Latch used to store a value:

  

  A	B	Action
  0	0	No change
  0	1	Reset
  1	0	Set
  1	1	Not allowed

• SR Nand Latch:

  

  A	B	Action
  0	0	Not allowed
  0	1	Store 1
  1	0	Store 0
  1	1	No change

Flip Flops

• D Flip Flop: A positive edge triggered flip flop storing D value:

  

  D	Q(t)	Q(t+1)
  0	0	0
  0	1	0
  1	0	1
  1	1	1

• T Flip Flop: A positive edge triggered flip flop toggeling its value:

  

  T	Q(t)	Q(t+1)
  0	0	0
  0	1	1
  1	0	1
  1	1	0

Note Feel free to submit pull-requests for more module implementations

3. Custom Modules

LogicRs allows you to create your own blocks implementing other and more complex behavior.

Custom modules can either be newly created using the New Module dialog or imported from an external .lrsmod file.

Creating a new module

When you create a new module, you'll be shown this popup:

Here, you can select the name of the module, the number of input and output connections.

Warning These settings cannot be changed afterwards currently!

After selecting "Ok", a new tab will appear with the module's contents:

Note If you closed this tab, you can re-open it by selecting "Edit Contents" from the module's context menu in the side bar.

You see two blocks already put in by default: These are the input/output blocks which receive and return values. They are double-sided and act like passthroughs to allow in-place debugging/testing of a single module. You cannot delete these blocks.

Between the two blocks, you can implement your own logic using the built-in blocks or other custom blocks.

Note Keep in mind, that recursive modules (i.e. Modules that depend on themselves) will not work and will cause the simulator to stop working until resolved.

Exporting Modules

To export a module, simply right-click on the respective module in the side-bar and select the "Export" menu item. You can then select an appropriate file name for your module.

Modules are stored using the .lrsmod file extension.

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