Use SpectreMDL to run PVT simulation

use command

spectremdl -batch batch.mdl -design design.scs

where the design file is something like:

simulator lang=spectre
global 0
parameters AVDD12=1.2 f_clk=10M
include "model.scs" section=tt
tran_x11 tran stop=300n errpreset=liberal write="spectre.ic" \
    writefinal="spectre.fc" annotate=status maxiters=5
alter_ss altergroup {
include "model.scs" section=ss
}
alter_ff altergroup {
include "model.scs" section=ff
}
alter_sf altergroup {
include "model.scs" section=sf
}
alter_fs altergroup {
include "model.scs" section=fs
}
alter_temp_low alter param=temp value=-45

and the batch file:

alias measurement tran_duty_cycle {
export real dc
run tran_x11
dc=dutycycle(V(OUT))
}
run tran_duty_cycle
analysis item,myAgs[]={alter_ss,alter_ff,alter_sf,alter_fs}
foreach temp from {-45, 45, 125} {
foreach AVDD12 from {1.08, 1.2, 1.32} {
foreach item from myAgs onerror='continue {
// change process corner
run item
run tran_duty_cycle
}
}
}
//run alter_ss
//run alter_temp_low
//run tran_duty_cycle as tran_duty_cycle_2