icfb (5.0.33_USR3.16.35)
====================
*) always use icfb to start the whole environment. Otherwise, some of the tool set, such as analog environment may not be initialized properly. (For example, if you start with a subset tool such as layoutPlus, the menu for analog environment may be gray color)

*) LVS fail. ( use analog environment to extract spice netlist first before using LVS )

*) Cadence LVS, if switch A / B input for a certain gate , it is not detected by LVS

*) whos
   who
   clear
   clear all
   format
 
*) clf  : clear current figure
   clc : clear command window
   close all : close all the figure windows

*) use fzeros to solve equation, see also people.clarkson.edu/~wilcox/ES100/eqsolve.htm

*) size (vector), length (vector)

*) eye : Identity Matrix

*) det : get the determinant

*) transfer function (s domain) : tf

*) frequency (bode plot) : freqs (s domain, bode plot), freqz (z domain), bode

*) filter design: fdatool, fvtool

*) display a message : disp (' abcdef ')
   use num2str to translate number to string, like disp ( [ 'xyz=' num2str (xyz) ] )

*) echo on/off to show the command executing even if that command ends with a semicolomn

*) figure : open a new figure window

*) "margin" to get phase margin and gain margin. Please note that the definition of the phase margin and gain margin may be a little different (need offset adjustment) from what says in some textbooks (such as Razavi's "Design of Analog CMOS IC"). If used without left-hand arguments, Bode plot will be shown with correspondent GM/PM marked on the graph.

*) step : to get the step response, on time domain (plot can be obtained as well through this function. On the plot, right click to get the pop-up menu, which would help to determine the settling time, rising time etc.)
   impulse : to get the impulse response
   impz : impulse response, plot can be obtained

*) find : to search for a particular element in the matrix

*) dec2hex, hex2dec : conversion between hex and decimal numbers

*) reshape : transform ( fold ) a particular vector ( 1 row or 1 column) into a matrix with designated number of rows and columns

Notes on "Modern Control Systems (10th Edition)",
by Richard C. Dorf and Robert H. Bishop, Pearson Prentice Hall, 2005
(
  http://wps.prenhall.com/esm_dorf_modctrlsys_10
  http://wps.prenhall.com/esm_dorf_modctrlsys_10/0,9419,1503606-content,00.html
 )

*) Polynomial operation:
+++>  roots : get the root of the polynomial
+++>  poly : reassemble polynomial from roots
+++>  conv: multiply two polynomials
+++>  polyval: evaluate polynomial at a given value

*) LTI (linear time-invariant) system
+++>  transfer function (tf) can be viewed as LTI object and added together (or apply other operations, such as division between each other)
+++> pole, zero, pzmap : get the pole and zero and pole/zero map of the LTI.

*) Block Diagram, loop reduction
+++> series ( functionally it is the same as multiplying two system transfer function)
+++> parallel
+++> feedback
+++> minreal : cancel the common factor in the numerator and denominator

*) Transfer Function and State Variable
+++> ss : state space representation ( as opposed to 'tf, transfer function representation')
+++> expm : calcuate exp(At) ( which is equal to state transition matrix)
+++> lsim : get time response of the system (with input and initial conditions)

*) logspace, linspace : generate vector in logarithm scale or linear scale
 
*) real, imag: real and imaginary part for complex number, imaginary number should use ' i '  or ' j ' for 'sqrt(-1)'

*) loglog to plot with x and y axis both in logarithm scale
   semilogx and semilogy : only x or only y axis is in logarithm scale

*) meshgrid and mesh to plot 3-D graph

*) rlocus to determine and plot the root locus
   rlocfind : can be used after rlocus to get a cross-hair on the plot to get the value of the selected point
   residue: to get the residue value, can also be used to convert between partial fraction expansion and polynomial expression

*) nyquist : to show the Nyquist plot. (In my opinion, it is easier to determine a system's stability through margin function than through Nyquist plot. However, Nyquist plot is the theoretic foundation that GM/PM is based upon. At least Nyquist plot offers another view for the same problem.)

*) pade : Pade approximation for exp( -s * T )

*) nichols, ngrid : Nichols Chart and correspondent grid

*) Controllability and Observability
   Use ctrb to get the controllability matrix, use obsv to get the observability matrix, use det to get the determinant of those matrix

*) acker : Ackermann's formula  to determine the state  variable feedback matrix for SISO  system

*) c2d, d2c : conversion between continuous-time system and discrete time system

Matlab Communication Toolbox

*) randint : generate random binary bits

*) bi2de, de2bi : convert between binary vector and decimal value

*) qammod, qamdemod, genqammod, genqamdemod :
    modulation/demodulation, genqammod/genqamdemod allows you to customize the constellation point

*) rcosine, rcosflt : RRC
-----------------------------------------------------

*) stem : stem plot

*) scatterplot : scatter plot

*) eyediagram : Eye Diagram

-----------------------------------------------------

*) awgn : AWGN


-----------------------------------------------------

*)  vitdec,  convenc,  poly2trellis : Viterbi, TCM

-----------------------------------------------------

*) biterr : BER

*) BERTool : BER analysis GUI tool

Secure file upload in PHP web applications
http://www.scanit.be/uploads/php-file-upload.pdf
 

 
"Tips for Linux",  great site for the tidbit of  Linux
http://www.codecoffee.com/tipsforlinux/index.html

Linux Service 

Magic SysRq key
=============
very useful for debug, especially if the system is in the middle of nowhere, you could use it to force the system crash and see the crash dump so that you might get a bit of idea where the endless loop is. On serial console, BREAK is the SysRq key. You could send BREAK through Tera Term's menu. See the Linux document for detail. 

*) kill -9 -1
kill every process owned by the user (Please use it wisely as a root)

*)  nohup example:

nohup hspice data_set04.sp > ! data_set04_b.lis &

http://www.comptechdoc.org/os/linux/usersguide/linux_ugbasicnet.html 

 Linux Network Setup

http://www.linuxcommand.org/ 

 How to Write Shell Script

fc -l
history
 

 show command history

xhost +
Discussion on xhost problem 

 use xhost+ command to fix the remote display problem on Linux box

 

 UltraEdit wordfile.txt for TI C54X Mnemonic Assembly

Satellite Signals,

 

 frequently used command/parameters for ARJ32