怎么理解voltus中跑出来的动态功耗

fnn小怪兽

我用voltus分别跑了静态功耗与动态功耗，在ug上看到了其对于static average power的解释如下：Switching power, which is the power consumed in the charging and discharging of interconnect capacitances. In most cases, this type of power consumption dominates because of large drivers having to drive large capacitive loads.
P = 0.5*CLV2 F*A where CL is the output capacitive loading, V is the voltage, F is frequency, and A is the average switching activity either from VCD or computed.
Internal Power, which is the power consumed in charging and discharging of interconnect and device capacitances internal to cell. Internal power can be divided into two parts:
Pin Power
Arc Power
Internal power is calculated by using the internal power tables provided in the .lib, which capture the characterized internal power over a range of input slew rates and external loading. The tables reflect the combination of both the internal switching and internal feedthrough power. Tables are generated as a result of spice simulation during library characterization. If k-factor power scaling parameters (for process, temperature, and voltage) are specified in the .lib file, the power engine will take them into consideration when calculating internal power (Note: timing related scaling factors are not handled by the power engine).
Leakage power, which is the power consumed by devices when they are not switching. It includes state-dependent leakage, which is leakage that depends on the state of the gate, that is, whether a transistor is on or off. This value comes from the .lib file if it exists. If k-factor power scaling parameters (for process, temperature, and voltage) are specified in the .lib file, the power engine will take them into consideration when calculating leakage power (Note: timing related scaling factors are not handled by the power engine).
并没有看到对于动态功耗的具体解释，我理解的动态功耗指的是在当前时间节点下翻转情况最坏时电路产生的功耗，不知道我理解的有没有问题，有哪位大佬可以指教一下吗

jake

Voltus static power和dynamic power用的是同一套算法，不同的输入，不同的配置，不同的使用场景。
Voltus static power本质上是平均功耗。
Voltus dynamic power算的是峰值功耗。把dynamic power的时间轴拉得长了，如设计最低频率时钟的整数周期，dynamic power也就接近平均功耗了。
写了一篇小文章，抛砖引玉吧。
http://blog.eetop.cn/blog-1592-6946981.html

一枚小兵

fnn小怪兽 发表于 2021-6-21 14:31
明白啦，谢谢大佬的指导！还有利用dynamic power跑出来的dynamic IR 只要关注最大的ir-drop就可以了吗？（ ...

dynamic IR要看，首先peak IR数值要满足signoff要求，再看IR map的分布是否致密均匀，是否有坏点，对应IR 最差点是怎样引起的，是因为用了大驱动的cell，还是peak电流导致，如果是peak电流导致，核对波形文件对应的时间的翻转是否与peak IR的情况一致。此外voltus的dynamic IR建议查看IVDD的结果

mwc1979

Voltus中所谓的动态功耗一般是指再VCD上找到一段单位时间的peak 功耗，可以细分到很短的时间。然后用这个peak功耗来作为动态功耗值去跑IR

yangsenlin1115

感觉voltus的静态分析跟动态类似，只不过时间拉成了无限长

一枚小兵

dynamic power一般不做参考，只是用来跑dyanmic IR，voltus会抓取瞬时的peak电流，计算该peak电流发生时的dynamic power

fnn小怪兽

一枚小兵 发表于 2021-6-18 18:00
dynamic power一般不做参考，只是用来跑dyanmic IR，voltus会抓取瞬时的peak电流，计算该peak电流发生时的d ...

明白啦，谢谢大佬的指导！还有利用dynamic power跑出来的dynamic IR 只要关注最大的ir-drop就可以了吗？ （也就是图中的48.41mv是否满足signoff的power标准）

littlechip

power signoff 静态IR和动态IR都要做的 标准嘛可以卡的严格一些 3% * 工作电压，请根据具体工艺要求来做决定，希望对你有帮助

wenfangsibao

一枚小兵 发表于 2021-6-18 18:00
dynamic power一般不做参考，只是用来跑dyanmic IR，voltus会抓取瞬时的peak电流，计算该peak电流发生时的d ...

一般情况下，动态功耗和静态功耗不是应该一样的吗？

一枚小兵

wenfangsibao 发表于 2021-6-21 19:16
一般情况下，动态功耗和静态功耗不是应该一样的吗？

不一样的，dynamic 的电流是peak的，所以如果报dynamic 的power会非常大，而static更偏向于平均的概念。可以看一下jake推荐的文章