Microwind and DSCH alternative: CMOS logic in your browser

Microwind is CMOS design software for education, from Toulouse, France, now at version 3.9: a layout editor and simulator that takes a chip from schematic to layout to simulation in one flow, with technology files down to FinFET (since 3.8) and nanosheet FETs (3.9, with a 3 nm rule file). It comes with DSCH, a logic editor and simulator that its site describes as the place to validate a logic architecture before the microelectronics design starts: hierarchical schematics, fast simulation with delay analysis, stuck-at fault injection, export to a SPICE netlist (PSPICE and WinSpice compatible) or Verilog, and models for the 8051 and PIC16F84 microcontrollers. Downloads require signing in on microwind.net. If what you want is to learn how CMOS transistors make logic, digiwleea covers that first step in the browser, with nothing to install.

What Microwind and DSCH are good at

Teaching real chip design. Microwind lets students draw transistor layouts in actual process technologies, work with real process rules, and simulate the extracted circuit, so they learn why a NAND gate's layout looks the way it does and how scaling changes speed and power. DSCH adds the logic level, with delays and fault testing. Together they cover the VLSI course from gate to silicon. (digiwleea is an independent project, not affiliated with Microwind or ni logic.)

How digiwleea is different

digiwleea stays at the schematic and logic level: you place NMOS and PMOS transistors as switches (every wire is 0, 1 or floating), build NOT and NAND, and go up through adders, latches, registers, RAM and an 8-bit CPU that runs a stored program, plus the assembly language behind it, through a 40+ level course where every part is checked against its truth table, with an AI tutor (Wleea). It has no layout, process technologies, parasitics or timing, so for a VLSI layout course Microwind is the right tool. It runs in any browser, which makes it a quick way to get the switch-level picture before layout. For the industrial flow, see the Cadence Virtuoso comparison.

	Microwind and DSCH	digiwleea
Level	Layout and process technology (Microwind); logic with delays (DSCH)	Transistors as switches, gates and up to a CPU
Simulates	Extracted layouts with parasitics; logic with timing and faults	Switch-level logic: 0, 1 and floating, no timing
Runs on	Desktop software, downloaded after signing in	Any modern browser, nothing to install
Learning path	Application notes and tutorials for VLSI courses	A 40+ level course from transistor to CPU, with an AI tutor
Price	Commercial education software	Free lab and Act I; Premium for the full course

The CMOS basics, live

Single gates. The inverter, NAND and NOR, then XOR and XNOR, transistor by transistor.
Complex gates. The AOI21, the majority gate and the 28-transistor mirror full adder.
Switches with a third state. The transmission gate and the tri-state buffer.
One transistor at a time. The MOSFET simulator and the CMOS lesson.

No sign-up is needed to start: open the lab and place your first transistor, or read the free theory course. The account (and the AI tutor) are optional.

More comparisons: HDL, FPGA and chip design tools

Icestudio alternative IRSIM alternative Yosys alternative Magic VLSI vs Electric VLSI Lattice Diamond alternative Cadence Virtuoso alternative Quartus Prime Lite alternative KLayout alternative Vivado alternative Tiny Tapeout Icarus Verilog vs Verilator vs GHDL Verilog vs VHDL

See for yourself: build a logic gate from transistors in the simulator, then follow the path from sand to an 8-bit CPU.

Open the digiwleea lab →

Frequently asked

What is Microwind used for?

Teaching and practising CMOS integrated-circuit design: drawing transistor layouts in real process technologies, checking them, and simulating the extracted circuits. Version 3.9 adds nanosheet FET technology.

What is DSCH?

The logic editor and simulator that comes with Microwind. It validates a logic design with delay analysis and fault injection before layout, and exports SPICE netlists and Verilog.

Is there an online alternative to Microwind?

For transistor layout, Microwind and desktop VLSI tools remain the options. For the switch-level side (how CMOS transistors make gates and how gates make a CPU), digiwleea runs in the browser with a free lab.