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Extracted Timing Model Contains Internal Pins With the Name of the Master ClockDescriptionQuestion:In an extracted timing model (ETM), there is an internal pin with the name of the master clock. What is the reason for it?Answer:In an extracted ti

I have many clock gating checks in my design. Some of my clock gating checks are complex, where the gating signal is launched by a different clock than the clock being gated. What are the rules for how the setup and hold clock gating checks are inferred?

I have a design in which a clock network switches between the original and divide-by-two version of a clock:Figure 1: Clock NetworkThe clock switching circuitry is designed so that I can switch between them "on the fly" during the low portion of.

I have a design with a path similar to the following:Figure 1: Design PathAll buffers have min/max delays of 1ns/2ns, with the exception of U3 which has a slow delay of 1.9ns instead of 2ns (represented with a slightly smaller buffer symbol). When ..

Why CMOS?Output of all CMOS cells will be very close to rail-rail (may not be in case of Pass Transistor) With constant input to any cell, power dissipation is only due to leakage currents. Power dissipation increase if activity factor is more (Short ci

Ways to fix setup violations:Setup violation occurs because of high delay in the data path or due to negative skew.Below are the ways to fix setup violation:Gate sizing Buffering Cloning Logic restructuring Vt swapping SkewingGate Sizing:Thi

WireWire appears as a simple line in schematic diagrams, connecting two components. But they are equally important as transistors because they affect speed, power dissipation and reliability of the circuit.Wire ModelGenerally we think of wire to be i

What is STA ?Static timing analysis is one of the techniques used to verify the timing of a digital design. STA is static since the analysis of the design is carried out statically and does not depend upon the data values being applied at the input pi

1.This section contains theexplanation of the timing exceptions forsn6xx000vpnnsmwrp000sa18SMS Wrapper.Compared withSMS 5.x, where data exchange between fast and slow clock domains happens, in SMS 6x, due to the clock switching mechanism, communicati...

PVTPVT是工艺、电压和温度的缩写。为了让我们的芯片在所有可能的条件下工作，比如在锡亚琴冰川-40°C和撒哈拉沙漠60°C，我们模拟了IC在制造后可能面临的不同过程、电压和温度的条件。这些条件称为corner。这三个参数都影响到cell的延时。我们将详细地讨论每个参数及其对延迟的影响。Process:工艺变化是指晶体管在制造过程中属性的偏差。在裸片die制造过程中，die的中心和边界处的区域可能会有不同的工艺变化。这是因为将被制造的层不能在整...

如图所示，数据由寄存器 F1 发出，寄存器 F3 捕获，完成CTS之后，由于clock skew原因，F1 到 F3 的hold，较难满足。在F1与F3之间插入一个latch，latch的时钟接start point时钟，即CLK1。latch为高电平透明，低电平锁存。则F1-F3的path分成两段。setup检查可以分两段检查，也可以是一段检查（latch作为组合逻辑看待）。hold检查只能分成两段检查。这样F1->L2的hold检查：在L2的close edge沿检查hold，因为是同

set_clock_groupsset_clock_groups 命令有三个选项：“-asynchronous”，“-logically_exclusive”，“-physically_exclusive”当 set_clock_groups 命令中多个 groups 被指定时，同一个时钟不能出现在不同的 group 中，但是可以存在于多次set_clock_groups 命令使用。例如 set_clock_groups -asynchronous -group {ClkA ClkB} -g..

1. launch clock and capture clock have the same clock frequencyPT工具默认检查行为：设置multicycle path，setup：3，hold：22. fast launch clockto slow capture clockPT工具默认检查行为：设置multicycle path，setup：3，hold：2，必须指定-start选项。3. slow launch clock to f...