$solvetimestep

$solvetimestep is a command for solving the transient behavior of the device. The format is

$solvetimestep
number_of_different_steps(Nt)
steptype $\delta t ~~   t_{total}$ par1 par2 par3 par4 ....    
steptype $\delta t ~~   t_{total}$ par1 par2 par3 par4 ....    
...
steptype $\delta t ~~   t_{total}$ par1 par2 par3 par4 ....    repeat Nt times

The number of parameters depeding on step type. Now we have 3 step types

Steptype  = 1:  

$\delta t,~~ t_{total},~~ vg_0$

 vg=vg_end for t<0, for t>0, vg=$vg_0$

Steptype  = 2:  

$\delta t,~~ t_{total},~~ vg_0 ,~~ A_{0} ,~~ \omega,~~ c_{0}$

$vg=vg_0 +  A_{0} \times sin\left( 2\pi \omega t + c_0 \right)$

Steptype  = 3:  

$\delta t, ~~t_{total},~~ vg_0 ,~~  A_{0} ,~~ \omega ,~~ c_{0}$

$vg=vg_0 +  int(A_{0} \times sin\left( 2\pi \omega t + c_0 \right))$

For example:

$solvetimestep
2
2 1.0e-10 1.0e-6 3.00 0.1 1.0e6 0.0 
1 1.0e-10 1.0e-6 3.20 
first run
 $vg=3.0 + 0.1 \times sin\left( 2\pi \times 10^{6} t  \right)$

then run
 $vg=3.2$