Note: Make sure your folders and file names don't contain any spaces.
Q1) Cygwin won't load irsim? (Symptom - window appears and disappears)
A1) Make sure you have the technology file (scmos25.prm) and a simulation
file (filename.sim) in your working directory and that you have set the path
to this directory in cygwin (e.g. by typing cd h:/my_asic_work.)
Also make sure that the tech file / sim file has the correct extension (i.e.
it should be .prm NOT .prm.txt .prm.zip or any permutation of this)
Also make sure you use the graphical Cygwin prompt, there is a link on your desktop.
Q2) I get an error to do with the connector minimum width in electric?
A2) Change the width and length of contact (by db clicking) from 5 to 6 lambda.
Q3) My circuit doesn't simulate in spice? It complains about not being able to find a operating point etc...?
A3) Firstly reopen your design in electric
and and check for errors manually, using F5 and correct these errors.
Failing this check that you have exported vdd and ground as power and
ground connections and not inputs.
Q4) How do I generate test input vectors for my spice simulations?
A4) Lookup the pwl command and use this. It should be in the following form:
{label} gnd {signal} pwl(time1 value1 time2 value2 time3 value3 ...)
Note that the label must begine with the letter v
Q5) lab2.elib won't work?
A5) Check it downloaded as lab2.elib not lab2.mp3
Q6) My ring oscillator doesn't simulate with the nand gate in irsim?
A6) Think about the level you are starting
the control input as and why this makes a difference? Also release the
output after the first cycle.
Q7) I keep getting an "iteration limit reached error"?
A7)
If you are sure that your design is correct, have checked in electric
and in the spice netlist, then try increasing the iteration limit using
the following command in your user_append.spi file:
.OPTIONS itl4=100
Q8) I cannot get irsim / cygwin working on my laptop?
A8) Firstly make sure you have installed cygwin with the X11 option checked.
Also ensure you have followed Prof Cheungs instructions (i.e. unzipping the two zip files to the cygwin directory.
If these 2 fail then copy the local directory from the machines on
level 9 - you can find this is c:\cygwin\user and replace the same one
on your machine with this.
Also copy over the .X11-user directory to your machine.
If this still doesn't work then try loading cygwin from the startxwin.bat file