rise_transition in .lib file

[tok47]

Halo ALL,

I am trying to cross match the lib file data with simulation output.

In lib file,
rise_transition ("del_1_6_6") {
index_1("0.24, 0.48, 0.96, 1.2, 2.4, 4.8");
index_2("1.86655, 6.86655, 11.8665, 21.8665, 36.8665, 51.8665");
values("1.0581954, 1.2011780, 1.5565619, 2.4754880, 4.0341566, 5.6333791", \

In .sp file, i refering to
* Measure Gate Output Transition Time
.MEASURE TRAN nc_optr_PAD
+ trig V(n_PAD) val = 9.0000000000e-01 td = 'nc_td' cross = 1
+ targ V(n_PAD) val = 2.1000000000e+00 td = 'nc_td' cross = 1

And in the simulation output file, for the high lighted one, nc_optr_pad= 5.290977344e-10.

This value nc_optr_pad= 5.290977344e-10, exactly half of 1.0581954e-09.

Can anyone explain to me why these 2 values are not the same?



Thanks.

 

[legend03u8z]

hi, you need to check the headlines in .lib,
if the measurements are from 30% ~ 70%, the transition time actually measured 40% of the voltage swing,
if are from 20% ~ 80%, the transition time actually measured 60% of the voltage swing,
after that, the presented date in the transition timing group should be the measurment result/slew_derate_from_libaray.
for example if the attribute "slew derate from library" = 0.5, the presented value will be (measured result)/0.5