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Liberate - Constraint search failed

iamKarthikBK

Greetings to the Cadence Technical Community!

I was trying to characterize a couple of sequential cells in Liberate when I came across this error.
I am using the -auto_index option and I've set the max_transition value to something really high (1e-05)

ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFRM1', r_pin:'RN', r_pin dir:'f', pin:'RN', pin dir:'f', type:'min_pulse_width fall_constraint' when: CK. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_23 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFRM1', r_pin:'RN', r_pin dir:'f', pin:'RN', pin dir:'f', type:'min_pulse_width fall_constraint' when: !CK. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_24 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFRM1', r_pin:'CK', r_pin dir:'f', pin:'CK', pin dir:'r', type:'min_pulse_width fall_constraint' when: (D * RN). This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_31 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFRM1', r_pin:'CK', r_pin dir:'r', pin:'CK', pin dir:'r', type:'min_pulse_width rise_constraint' when: (D * RN). This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_32 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFRM1', r_pin:'CK', r_pin dir:'f', pin:'CK', pin dir:'f', type:'min_pulse_width fall_constraint' when: (!D * RN). This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_33 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFRM1', r_pin:'CK', r_pin dir:'r', pin:'CK', pin dir:'f', type:'min_pulse_width rise_constraint' when: (!D * RN). This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_34 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFM1', r_pin:'CK', r_pin dir:'f', pin:'CK', pin dir:'r', type:'min_pulse_width fall_constraint' when: D. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_11 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFM1', r_pin:'CK', r_pin dir:'r', pin:'CK', pin dir:'r', type:'min_pulse_width rise_constraint' when: D. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_12 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFM1', r_pin:'CK', r_pin dir:'f', pin:'CK', pin dir:'f', type:'min_pulse_width fall_constraint' when: !D. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_13 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFFM1', r_pin:'CK', r_pin dir:'r', pin:'CK', pin dir:'f', type:'min_pulse_width rise_constraint' when: !D. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, save and review the simulation results for deck: mpw_14 using extsim_save_passed and extsim_save_failed. Possible causes include: 'constraint_delay_degrade' too large; 'constraint_delay_degrade_abstol' too large; 'constraint_check_final_state_threshold' too large; estimated search range too small (see constraint_search_bound). Modify the constraint parameters and rerun.
WARNING (LIB-422): (char_library): 2 cells failed during characterization. Review the .log file for previous Warnings and Errors that could explain the failures. Update the Tcl script and rerun.
ERROR: Process ID out of range.

What could be the reason? I am not setting any constraint_delay parameters.
Is it just the max_transition?

Thanks in advance!

Parents Reply Children
  • in reply to Guangjun Cao

    Hi ,

    I was using -auto_index, and because of my max_transition, liberate was looking at a very large search space for the arc.
    This issue was resolved by reducing the max_transision to something more reasonable (an approximate), and the characterization passed.

    Thank you for your help!

    P.S. sorry, my reply was a draft here.

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