KiCad used for VLSI?


#1

Hello, i am wondering could the KiCad be used for VLSI design, since it would be perfect for it? I mean, does it have all the nessecary elements to do VLSI design?
Thanks


#2

With vlsi do you mean chip design?
If so how come you think a pcb design tool would be perfect for such a task?


#3

Try something like Electric and LTSPICE.


#4

Because it came up when i googled VLSI tool, it has nice working interface and supports 3D


#5

Tried Electric, and i thanks for suggesting LTspice, i will give it a try!


#6

None of which are relevant for VLSI/ASIC design.

If you are doing ASICs, you are most likely working with an HDL (VHDL or Verilog) and synthesizing to your fab’s primitives library. You will spend most of your development time with a text editor and an HDL simulator.


#7

Could something like kicad be used for integrated circuit layout? Maybe. All you really need are gerber files to send to the fab. IC tapeout in theory isn’t that much different than for PCBs. Should you? Probably not. Especially depending on the complexity of the circuit. Are you doing a 20 transistor analog opamp design on a 5um BJT process for a university class project? Or something with thousands or millions of devices on a deep submicron CMOS process? Are you going to use some other tool for DRC checking? IC process have a lot more rules that are more stringent and differ for each layer (e.g. polysilicon gate layers, vs. n-well regions vs. metal layers). I’ve certainly used more primitive tools to produce functional chips. A long time ago I use LASI for a class project. If anyone had tried using kicad as an IC layout tool, they’d probably be on the Mosis User Group. If nothing else, ask for opinions on low cost / free software recommendations for IC layout if that is your primary goal.


#8

This came up about a month ago.


#9

Once upon a time all IC design was done with tools very similar to kicad. Then designs grew and you couldn’t plop down gates fast enough to meet schedule so we dumped schematic capture and now use a HDL -> synthesis -> standard cell for most IC design.

You could use kicad to do logic design as long as your chip was about the size of a Intel 8008 cpu. IC’s are now in the billion gate range and IC tools have added new features to deal with the size and complexity of big data. None of these new features have been fed back into schematic capture tools.

Kicad’s biggest shortcoming is that it doesn’t handle buses. The thing you call a bus in only an array. A true bus is something like the wishbone bus with multiple signals going both directions in the hierarchy. Add that to kicad and it would make a great system design tool.

John Eaton


#10

25+ years ago I used to design Xilinx 2000 and 3000 series FPGAs using Orcad.
Once the 4000 series came out, I was forced to switch to VHDL by the complexity getting out of hand


#11

Once upon a time all IC design was done directly on film on a large light table, so what?[quote=“ouabacheDesignworks, post:9, topic:8465”]
IC’s are now in the billion gate range
[/quote]
Transistor count is a more useful metric with FPGAs currently hitting 30 billion. NAND Flash has even higher densities than that. But considering the op is here asking about VLSI tools I hardly think he needs the complexity of “big data” tools.

Seriously? This is the biggest shortcoming? Wishbone bus? [quote=“Greg, post:7, topic:8465”]
All you really need are gerber files to send to the fab.
[/quote]
Do you know of a Fab that accepts Gerber files? While the industry standard is OASIS I believe GDSII is still common.

Unfortunately that is what some believe, but it couldn’t be further from the truth.

The short answer to the op’s question would be no. The longer answer would be definitely not.