Probably before the distant 90nm, leakage power in the library where indeed be described as a constant value. But start 90nm, To be more precise, in the Library leakage power is no longer a constant value, but rather is modeled as a function of input state. So the foundation or library, in a library in variables associated with leakage roughly:
library(my_lib) {
leakage_power_unit :"1nW";
default_leakage_power_density :0.0;
default_cell_leakage_power :0.0;
cell_leakage_power :53057.365200;
leakage_power(){
when :"!A & !B & !CI";
value: ...;
power_level:"VDD";}
}
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Leakage_power_unit: marked leakage power units, if all the library are not defined in the variable, each instrument will have its own default units, such as Genus default with nW.
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cell_leakage_power: Flag fixed leakage power value, if there are no library definition of the variable, or the variable is a negative value, with the value default_cell_leakage_power tool if default_cell_leakage_power not specified, with the value of the cell multiplied by the area of default_leakage_power_density be a calculated leakage values, if these three variables is defined, the value 0 of the leakage.
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leakage_power () {}: This section is used to define the input state associated with the leakage power, wherein "when" define the state of the input, if a certain state is not defined, with the value defined cell_leakage_power calculating leakage; power_level with multi-cell voltage with which the voltage is specified in the relevant leakage power.
1. If the library does not define cell_leakage_power there is no definition of default_cell_leakage_power only defines default_leakage_power_density, then:
cell_leakage_power= area *default_leakage_power_density
2.
Take AND2X2 this cell, for example, it has a total of four combinations of input state, lib defines only three states, as well as defining cell_leakage_power, so for the state not defined, with the value cell_leakage_power specified in the calculation. Suppose, A probability in state "1" is 0.6, B in the probability state "1" is 0.3, then the cell is leakge power is:
prob(!A) x prob(!B) x yy11+ prob(!A) x prob(B) x yy22 +prob(A) x prob(!B) x yy33 +prob(A) x prob(B) x YYYY=0.4 x 0.7 x yy11 +0.4 x 0.3 x yy22 + 0.6 x 0.7 x yy33 +0.6 x 0.3 x YYYY
In a real project, if no file is read into the activity, different tools will have to calculate the probability of each cell based on the input pin of a default or a specified probability, different tools will be a corresponding command to report the current probability is how much as Genus can use the command: report instance -power, relevant information can also be obtained by the following attribute:
lp_probability_type
lp_default_probability
lp_computed_probability
Immature tips: find a cell in a different tool in each report it to the leakage, then according to those set forth herein, to observe the behavior of the tool, it will be in the palm of your master.