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Changing RTL is always the easiest option. Have you got register merging turned off? Than can help reduce the register fan outs. All false paths and multi cycle paths specified? Finally you can try overconstraining a single path using a set max delay, but this can often make it harder to route adjacent nets and is a rather tedious job. Why (...)
Yes Yes, the synthesis tool has options for how hard it will work in order to improve timing; random number seeds that affect the fitter; design space explorers that iterate on various synthesis parameters in order to find something that works. Things like that. Peruse the synthesis tool documentation since the options are all
Hello all, I am aware of a similar post on edaboard with this question. However I am unable to continue that thread as it is closed. Here I am asking the similar question. Will ATPG tool be able to generate patterns which simulate false paths and multi-cycle paths? I am sure false paths will not be (...)
Hey, false path constraint is much more strict, as you are saying that paths between launching and capturing flip flops will not exist, may be due to some architectural condition. Hence, tool will not time those paths. I guess SCP is single cycle paths. I am not sure about SMT. Thanks, Abhishek https://www.e
In which stage of the design flow we get an idea about the false paths and multicycle paths in the design? Which tool will report them? In RTL level, we are left with the logic of the design only and we will have no idea about how the tool will synthesize different paths in the design. The tool will synthesize the design (...)
While doing synthesis if there are multiple clock domains we can either use set_clock_group or set false paths for all the paths among the multiple clock domains. What the advantages and disadvantages between these two ways of either using set_clock_group or setting false paths among clock domains.
There are several ways to help remove timing errors. They should be done in this order. 1. Modify your code and break up the logic on the failing paths? are there several sequential LUTs in the failing path? can it be broken up with extra pipeline registers? Also - are the failing paths into or out of DSPs or RAMs? these have a fixed location, so w
Hi everyone, What is the difference points between set_false_path & set_disable_timing? When should we use which suitable command? BR,
Hi. I'm trying to implement including false path and multi cycle path RTL code for test design compiler. So does anyone know where some example codes are ?
I understand that a set_multicycle_path can be specified between two different clock domains. If the source and destination clocks are synchronous I believe there isn't much confusion. But if the clock domains are asynchronous, how does the STA tool handle it? I haven't seen this getting used in my experience yet, just curious about
Hi, During stuck-at testing, what will happen to false and multicycle paths from the functional logic. Will stuck-at testing take them as faults? How does ATPG tool handle false and multicycle paths?
Hi, I am trying to enumerate all false paths of the circuit using PrimeTime. I tried -true -false and -justify switches but it seems that these options have been made obsolete since the 2011.12 release of PrimeTime and are no longer supported. I am wondering whats the new commands? Thanks
In my design, there are two independent clocks in functional mode and cross clock path are defined as false path. But in DC scan mode, these two clocks will be grouped into a single scan clock. Do we need to fix timing violation on these cross clock paths which become driven by the same scan clock in scan mode?
Hi All, I am using Xilinx's Vivado 2013.3 for generating the *.bin file. There are a lot asynchronous paths in my design. for example if I have grouped the signals like : # in CLK1 domain set GROUP1 ; set GROUP1 ; set GROUP1 ; # in CLK2 domain set GROUP2 [get_cells {sig_
I have a simple question about false paths: why do they exist? I mean, if they can never "happen", why does the synthesis tool generate (or keep) them? I'm not talking about asynchronous paths, but paths that will never really occur. Like this one: Thanks in advance
false path should be provided by the designers.
1- the designer who made the design could provide the paths which could be relax via false path or multi-cycle. 2- if your design meet the timing/area/power, you do need to add constraint. 3- if you are not able to reach the timing, you need to analyze the worst path and confirm, that a true path. if it is a true path, the design need to be modif
You are talking about CDC checks for making sure e.g. the set of signals crossing the domain do not have a delay spread larger than one receiving-domain clock period? You still might want to declare a FP between the unrelated clocks, e.g. if you are specifying min/max delay constraints as point-to-point timing exceptions only for the actual CDC pa
Well, if your STA is clean and you have a netlist simulation error, two solutions, you have some false paths which mask your sta, or the case is not " real" in your simulation.
in clock domain crossing, you set false path for hold while doing synthesis because two clocks are asynchronous and timing cannot checked. But you set set_max_delay and set_min_delay on these paths. so that data should reach after specified delay.