Which of the following adds some margin into the system to account for variation in clock network (source, network)?
A. set_driving_cell
B. set_clock_skew
C. set_clock_uncertainty
D. create_generated_clock
Propagated clocks are identified by which command?
A. Rpt_clock_ports
B. Report_QOR
C. Report_annotated_parasitics
D. Report_clocks
Which command is used to identify the endpoint port of a design which has the worst slack for out_setup?
A. Report_analysis_coverage -status violated -check out_setup
B. Report_annotated_parasitics -status violated -check out_setup
C. All
D. Report_timing_path_short -to [all_outputs *] -check out_setup
Answer (2)
The correct answers to the questions are as follows: C. set_clock_uncertainty for adding margins in clock networks, D. Report_clocks for identifying propagated clocks, and D. Report_timing_path_short -to [all_outputs *] -check out_setup for identifying endpoint ports with the worst slack for out_setup.
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The question you're asking is related to digital design and verification, typically a part of Electronic Engineering, particularly dealing with clock-related constraints in digital circuits.
Let's break down the question into the components:
Margin in Clock Network for Variation :
The purpose of adding margin into the system is to ensure the reliability of clock signals, taking into account any possible variations or delays.
Correct Answer: (C) set_clock_uncertainty
The set_clock_uncertainty command is used within EDA tools to add some margin by specifying an uncertainty value that accounts for variations in clock paths and the source of the network.
Propagated Clocks Identification :
Propagated clocks are clocks that have their transitions followed through the network to ensure timing slack and other constraints are met.
No specific answer can be confidently given based on the provided options. This is often tool-specific and varies in syntax and implementation between different tools.
Identifying Endpoint Port with Worst Slack :
The slack indicates the timing margin, and negative slack means a violation of timing constraints (usually setup time constraints).
Correct Answer: (A) Report_analysis_coverage -status violated -check out_setup
The command Report_analysis_coverage -status violated -check out_setup would most likely be useful in identifying where the worst slack occurs, although this may be tool-dependent and could vary.
In digital circuit design concerning timing analysis, engineers often employ these commands within EDA tools to ensure that the chip meets its timing specifications under all operational conditions.
