what is the reason of using index values in .lib files

[Manochitra]

hi all...


lu_table_template(cnst_ctin_rtin_3x3) {
variable_1 : constrained_pin_transition ;
variable_2 : related_pin_transition ;
index_1("1, 2, 3");
index_2("1, 2, 3");

In the above syntax we use index values.. like this we use to mention index values in many places in .lib files ....anyone knw the reason for using these index values...

thanks in advance

 

[oratie]

This is because the delay/setup/hold... are depends on input_pin_transition and output_pin_load. In your example, seems this table if for setup (or hold). The value of setup depends on input_pin transitions, and the index values are exactly the length of these transitions.

 

[Manochitra]

thank you...how they choose values of index in the following syntax....



fall_power(pwr_tin_7) {
index_1("0.0171371, 0.0295301, 0.0730322, 0.156106, \
0.28553, 0.467128, 0.706085");
values("0.000311845, 0.000304249, 0.000296142, 0.000291984, \
0.000289276, 0.000288749, 0.000287177");
}



fall_constraint(cnst_ctin_rtin_3x3) {
index_1("0.0171371, 0.16989, 0.706085");
index_2("0.0171371, 0.16989, 0.706085");
values("-0.00995, 0.043643, 0.156575",\
"-0.06353, -0.019959, 0.093043",\
"-0.166466, -0.142793, -0.059715");
}


plz explain me in detail....

 

[oratie]

The fall_power table (1-D table): the first index value "0.0171371" corresponds to first power value "0.000311845".

The fall_constraint table (2-D table): the first index_1 value "0.0171371" corresponds to the first line of values, the second index_1 value "0.16989" - to the second line of values. The index_2 values are responsible for selection of columns in the values.

So, fall_constraint (index_1=0.16989; index_2=0.706085) = 0.093043 .