Students from these colleges already practise here.
Cornell
IIT Madras
IIT Tirupati
NIT Rourkela
IIIT Kottayam
NIT Surathkal
IIT Kharagpur
IIT BHU
BITS Pilani- and more
You read about flip-flops
for a whole semester. Here you clock one.
Every problem ends the same way: your design runs against the problem’s tests and you see exactly where it passed and where it didn’t. That is the feedback a lab is meant to give you, and rarely has the time for.
Your design actually runs
We simulate what you submit against a test bench. If it works but looks nothing like our solution, it still passes.
Draw it or write it
Some problems want gates and wires, others want Verilog. Many topics come in both, so you can build a mux and then write one.
Open a tab and start
You don't need to install Vivado or book a lab slot. The result is back before you look away from the screen.
More than 1,300 problems
The first is a single gate and the later ones are pipelined datapaths. Every step in between is there too.
See why it failed
A failing test shows you the waveform or the truth table, so you can point at the edge that broke instead of guessing.
Follows your syllabus
Topics come in the order your ECE or EE course teaches them, then carry on into GATE and interview RTL.
Start at one logic gate. Finish at a synthesis report.
Wire it up first.
The Verilog makes more sense after.
Drag gates onto the canvas, connect them and flip an input. You see the signal move through every wire, which is the part a diagram in a textbook can never show you.
- Component library
- 60+ parts
- On every run
- Truth table
- Verdict
- About a second
Write Verilog.
Verify in seconds.
The test bench is already written, so you only write the module. Every run also gives you a synthesis report, which tells you whether what you wrote is hardware or just code that happens to simulate.
- Languages
- Verilog, SystemVerilog, VHDL
- On every run
- Waveform and synthesis report
- Verdict
- About a second
Frequently asked questions
A practice site for digital electronics and HDL. You solve problems by building circuits or by writing Verilog, SystemVerilog or VHDL, and a simulator checks your work against a test bench. You find out whether your design works, and if it doesn't, where it went wrong.
Verilog, SystemVerilog and VHDL in the RTL editor, and gates and wires on the circuit canvas. Many topics exist in both, so you can build a design on the canvas first and then write the same thing in HDL.
Yes. Signing up is free, every skill track opens with free problems, practice contests are open to everyone, and you get hints from Codu, the tutor built into the workspace. Pro opens the premium problems in every track and the weekly and special contests.
When you submit, your Verilog or your circuit is compiled and simulated on our servers against that problem's own test bench, not compared with a stored answer. You get the waveform or the truth table and a result for each test case, usually within a second.
Mostly ECE and EE students, people preparing for GATE, and anyone trying to land a VLSI internship or a first job in chip design. Plenty of CS students use it too, to see what is underneath the code they write.
No. The beginner tracks start at single logic gates and work up to FSMs and RTL design one step at a time. If you know what AND and OR do, you can start.
Yes. VLSI interviews keep coming back to the same ground: FSMs, counters, FIFOs, timing and reading a waveform. All of it is here as problems you have to solve yourself, which is what an interviewer is really testing.
No. There is no toolchain to set up and nothing to download. The compiler and the simulator run on our servers, so a browser is all you need, though the canvas and the code editor want a tablet sized window or larger.
LeetCode is for software algorithms. Codiode is the same idea for hardware: you get a problem, you submit a design and it runs against tests. The difference is that your answer is a circuit, and it has to work on every clock edge.
We work with these colleges to set practice for their own students.
Start with one gate. See how far you get.
Sign up with Google or email and you can be solving in under a minute. Everything you finish is saved to your profile.