后端标准单元库-Liberate for library characterization

亭ting

之前都是对组合逻辑单元，用liberate生成lib，虽然结果可能不是特别正确，但是报错的地方很少。但是当加入了一个时序的DFF触发器后，在生成中出现了很多错误。类似这样的：ERROR (LIB-52): The constraint search failed to find a solution within the search range for arc of cell:'DFM1RA_st', r_pin:'CK', r_pin dir:'r', pin:'D', pin dir:'r', type:'hold_rising rise_constraint', vector:'RRxx'. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, review the saved simulation results for deck: hold_5. 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:'DFM1RA_st', r_pin:'CK', r_pin dir:'r', pin:'D', pin dir:'f', type:'hold_rising fall_constraint', vector:'RFxx'. This cell will be marked as failed and the constraint data will be set to: 1.0 (see constraint_failed_value). To debug, review the saved simulation results for deck: hold_6. 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.



请问有人见过这样的问题吗，按照它提示的'constraint_delay_degrade'，'constraint_delay_degrade_abstol'改的很小了，也是不对，不知道什么原因？

亭ting

回复 1# 亭ting


   你好，我现在遇到了跟你这个一样的问题，之前都是生成组合逻辑没问题，现在加了一触发器就这样了，请问你是怎么解决的呐？