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Sep 2 2010

Logicly’s 2nd Update: Flip-Flops! (and more)

by Josh Tynjala

Today’s update to Logicly includes the most-requested feature of all time! Seriously, I’ve been getting it ever since I first put the prototype of Logicly on my personal blog two years ago. We now have flip-flops! With this little addition, it becomes a lot easier to build more complex circuits (though I’ve seen a couple screenshots from folks who built multiple flip-flops by hand… you’re all crazy!)

Screenshot of Logicly Preview 2

Here’s a full list of what’s new in this Logicly update:

  • SR, D, JK, and T flip-flops. The SR flip-flop is a master-slave implementation with negative edge-triggering. The others are based on IC 7474 and have positive-edge triggering along with preset and clear asynchronous inputs.
  • Push Button. Generates a high signal (true) when you press the mouse down. Goes back to low signal (false) when you release.
  • Constant Low and High input signals.
  • Label. Display some helpful descriptive text in your creations. Supports multiple lines.
  • Settings Window
    • Change the size of the editing surface grid (in pixels).
    • Toggle Snap to Grid.
    • Toggle auto-start of simulation when switching to Simulate perspective. Now you can start with the simulation in a paused state.
    • Change the appearance of connection wires between curves and lines.
    • Change each of the signal colors (high, low, and unknown).
    • Change the default “float” signal (it’s how unconnected inputs are interpreted). The default is still Unknown, like before, but now you can choose High or Low as well, if you prefer.
  • Property Editor Window
    • Change update frequency of Clock control.
    • Set startup signal of Clock and Toggle Switch.
    • Change the text of the Label control.
  • Simulation Updates
    • Design perspective is no longer “powered”. Any level of simulation, even without Clocks, must be done in the Simulate perspective.
    • Advancing the simulation by a step now controls both Clocks and propagation. Previously, propagation still happened automatically when the simulation was paused, and it could theoretically get out of sync with the clocks.
    • Improved performance of propagation.
  • A new sample demonstrates how to create a ripple counter with T flip-flops. It also includes the High constant, a Push Button, and a couple of Labels.

A variety of small bug fixes got in there too. This is a very solid release with more stability and a ton of new features that I know you all will love. We’re getting closer and closer to the release of the desktop app, and I’m pretty excited.

With that in mind, what else would you like to see Logicly do? We’ve got flip-flops now, but I know everyone has more cool stuff that they’d like to see. I put up a new form for requesting features or filing bugs, and I hope you won’t hesitate to use it:

File Bug Reports and Feature Requests Here

That goes straight to my inbox, and I take all feedback very seriously. Please share your most-desired features. You can also leave a comment here on the blog too, or post something on the Logicly Facebook page (don’t forget to Like it). You can even send a tweet to @logicly. Keep the great ideas coming!

From → Announcements

One Comment
  1. Micro Farad

    Hey! I am NOT crazy! Just because I made a shift register that serializes data with RS flip flips and… *mumbles on*

    I made a multiplying thingy…
    Here are some screen shots…
    http://www.mediafire.com/?aw86o1vapbe5b37

    2 bit binary multiplier
    Concept is easily extended to any size…

    The way it works is it takes the first number you multiply by, and stores it in the back of a shift register. This register, the long register, has a+b-1 units, where a is the number of digits in the first number to be multiplied, and b is number of digits in the second number. The second number is stored in another register, the short register, which is b units long. A ripple adder (cascading adder made of full adder units) sums the values in the accumulator register and the long register and output is stored to the accumulator register on a high clock signal, if the most significant bit in the short register is 1. On a low clock signal the long register is shifted so that the least significant bit is discarded, the bit shifted in is low. At the same time, the short register is shifted so that the most significant bit is discarded, and the bit shifted in is low. The rest is frills for input, resetting, clocking, display…

    The column of gates on the right is the ripple adder. The column of JK flip flops beside it, and the JK flip flop in the upper left hand corner, comprise the accumulator register. The column of JK flip flops next to the accumulator is the long register. The two JK flip flops in the center at the top comprise the short register. The four switches, two rows of two, grouped together, are the numbers to be added. The button next to them loads in the numbers to be added. The switch to the left turns calculation on or off, for demonstration purposes, though should be off when the button is being pressed. The four lights are the output. The T flip flop is part of the clock.

    9 JK flip flops
    1 T flops
    1 High
    1 Low
    6 XOR
    9 AND
    3 OR
    8 NOT
    8 NAND
    5 Switches
    4 Lights
    1 Clock
    1 Button

    34 Total Gates
    10 Total Black Boxes
    7 Total Outputs
    6 Total User Controls
    4 Outputs
    55 Total Logic Elements

    113 Total Wires

    #
      

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