Because of this, I might see a 2:1 clock mux in logic(where the sources are pins or PLLs) and the user doesn't do anything special and it all works out. They just cut timing between the two source clocks because they're not related. If they are related, the...
The out of these pll muxes are fed to one more mux. The final output of this mux is fed to the logic. Now I am able to constrain w.r.t the output of pll clock muxes. But I want to constrain my output data pins w.r.t to 4 input clocks that comes to FPGA. Please r...
而且SCAN MUX的D1端的insertion delay值需要根据上面第四点得知的clock tree差值来设置。这样就可以确保整个设计中无论在func或scan模式下,setup和hold的timing都是比较理想的。 考虑到很多工程师在时钟树综合CTS这块还是比较薄弱,小编计划近期开设社区的第三个训练营课程——复杂时钟结构的时钟树综合训练营。这个课程中...
手把手教你分析时钟树综合的log(附社区历史干货合集等福利) 而且SCAN MUX的D1端的insertion delay值需要根据上面第四点得知的clock tree差值来设置。这样就可以确保整个设计中无论在func或scan模式下,setup和hold的timing都是比较理想的。 考虑到很多工程师在时钟树综合CTS这块还是比较薄弱,小编计划近期开设社区的第三...
这种情况也比较常见,主要原因是constraint不完备导致的。一个典型的情况是当你看hold violation时发现有500ps violation,乍一看就是clock skew严重不balance导致的。仔细分析后发现原来capture clock path上有一堆的data。这种情况小编称之为data和clock互穿或交叉。解决方法要么是disable timing arc,要么就是设置clock sen...
The Set Clock Groups (set_clock_groups) constraint allows you to specify which clocks in the design are unrelated. By default, the Timing Analyzer assumes that all clocks with a common base or parent clock are related, and that all transfers between those clock domains are valid for timing ...
set_clock_groups Constraint Tips 3.6.5.6. Accounting for Clock Effect Characteristics 3.6.5.7. Constraining CDC Paths 3.6.6. Creating I/O Constraints 3.6.7. Creating Delay and Skew Constraints 3.6.8. Creating Timing Exceptions 3.6.9. Using Fitter Overconstraints 3.6.10....
. I changed my constraint to this format: -from&-to. In this case you have to useget_cells...
www.national.com/see/timing 1-1 Clock Conditioner Owner's Manual Structure of a Clock Conditioner Figure 1.1 shows a clock conditioner architecture. A clock conditioner conditions the clock signal that is applied to the Reference Oscillator (Ref Osc) input as shown in Figure 1.1. The Ref Osc ...
The MUX and DEMUX structure is shown in Figure 3. By applying proper control signals to the MUX and DEMUX respective clock signal got selected for proper operation. The real challenge was for the RTL designers to come up with an idea like this and implementing the same. Meeting timing in ...