Windywast
Newbie level 3
Hi, I have two sets of two SPEF files (fast/slow corners, respectively) that I wish to read into Innovus and run STA with MMMC. For each set, I have created two rc corners that are from the two SPEF files I have, like so:
However, my problem is that even though the two sets of fast/slow SPEF files are different, they have the same slack values in the reports. Even if I manually modify the spef files to have unrealistic cap values, the slack does not change. Since several warnings jump out when setting the analysis view:
Does the default values actually overwrite the cap/res values in the spef file? Is there a way to force the program to use the values in the spef instead? Thanks!
Code:
# # MCMM setup
create_constraint_mode -name CON -sdc_file test.sdc
create_library_set -name WC_LIB_SLOW -timing slow.lib
create_rc_corner -name _slow_rc_corner_
create_delay_corner -name WC_SLOW -library_set WC_LIB_SLOW -rc_corner _slow_rc_corner_
create_analysis_view -name WC_SLOW_VIEW -delay_corner WC_SLOW -constraint_mode CON
create_library_set -name WC_LIB_FAST -timing fast.lib
create_rc_corner -name _fast_rc_corner_
create_delay_corner -name WC_FAST -library_set WC_LIB_FAST -rc_corner _fast_rc_corner_
create_analysis_view -name WC_FAST_VIEW -delay_corner WC_FAST -constraint_mode CON
spefIn fast.spef -rc_corner fast_corner
spefIn slow.spef -rc_corner spef_corner
setAnalysisMode -analysisType onChipVariation -cppr both
set_analysis_view -setup [list WC_SLOW_VIEW] -hold [list WC_FAST_VIEW]
report_timing -early > fast.report
report_timing -late > slow.report
However, my problem is that even though the two sets of fast/slow SPEF files are different, they have the same slack values in the reports. Even if I manually modify the spef files to have unrealistic cap values, the slack does not change. Since several warnings jump out when setting the analysis view:
Code:
**WARN: (IMPEXT-2776): The via resistance between layers M1 and M2 is not defined in the capacitance table file. The via resistance of 4 Ohms defined in the LEF technology file will be used as via resistance between these layers.
Does the default values actually overwrite the cap/res values in the spef file? Is there a way to force the program to use the values in the spef instead? Thanks!