.lib

  1. slew_lower_threshold_pct_rise : 30.00
  2. slew_upper_threshold_pct_rise : 70.00
  3. slew_upper_threshold_pct_fall : 70.00
  4. slew_lower_threshold_pct_fall : 30.00
  5. input_threshold_pct_rise : 50.00
  6. output_threshold_pct_fall : 50.00

input_threshold_pct_fall : 50.00
output_threshold_pct_rise : 50.00
slew_derate_from_library : 0.50

To transition, general library data based on 10% – 90%, some library data based on 30% – 70%, but times 2 in order to modify range from 10% to 90%. 40 – 80. If it happened, it would demonstrate slew_derate_from_library : 0.5.

It doesn’t effect delay value, as delay calculate 50% – 50%.
But it would effect:
1. 2D table input_transition scale.
2. timing group: rise_transition() fall_transition() value.

Old process, measure cell rise/fall transition base on 10% – 90% VDD, range is 80%.
New process, measure cell rise/fall transition based on 30% – 70% VDD, range is 40%.

In order to map old process, new library transition maping to 10% – 90%, value times 2.

For example, 30% – 70% measurement index 0.1 0.2 0.5 rise/fall transition, in liberty format file:
index_1:input_transition index is 0.2 0.4 1.0
rise_transition/fall_transition LUT data ACTUAL value times 2.

cell_rise (delay_template_8x8_0) {
index_1 (“0.0032, 0.0055, 0.01, 0.019, 0.0369, 0.0729, 0.1448, 0.2887”);
index_2 (“0.00193, 0.01051, 0.02766, 0.06197, 0.13059, 0.26782, 0.54228, 1.09121”);
values ( \
“0.0053704, 0.0071752, 0.0104245, 0.0166787, 0.0291298, 0.0540088, 0.10373, 0.20322”, \
“0.00647746, 0.00841524, 0.0118038, 0.0181688, 0.0306396, 0.0554789, 0.105171, 0.204444”, \
“0.00847891, 0.0106114, 0.0142923, 0.0209484, 0.0335626, 0.0584134, 0.108127, 0.207598”, \
“0.0123298, 0.0146434, 0.0187414, 0.0259847, 0.039199, 0.0643416, 0.114266, 0.21361”, \
“0.0188298, 0.0221453, 0.0268126, 0.034889, 0.0492921, 0.0756078, 0.12597, 0.225112”, \
“0.0295561, 0.0348098, 0.0417188, 0.0511548, 0.0672525, 0.0959029, 0.148602, 0.249146”, \
“0.0471108, 0.0553811, 0.0662697, 0.0805945, 0.0997046, 0.131706, 0.189114, 0.294539”, \
“0.0750624, 0.0891747, 0.10672, 0.129267, 0.158638, 0.196929, 0.260907, 0.375785” \
);
}


 

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