比如静态时序分析STA的时候找不到generated clock和source clock相位关系,会将generated clock的source latency 设置为0。 如下图为一个简单的数字IC电路及其波形图。 create_clock -period 10 CLK create_generated_clock -name CLKdiv2 \ -divide_by 2 \ -source CLK\ [get_pins Udiv/Q] 根据上面定义,genera...
PT选择,generated clock内的worst-case path来计算generated clock的source latency。 source latency表示源时钟自带的延时,network latency表示CTS之后clock tree insertion delay,所以DC阶段不需要设置network latency, 除非不同的clock有不同的clock tree insertion delay,又不想平衡这些clock, Pulse clock:算是一种特殊...
这些关系由桥梁source clock嫁接,所以需要名曲generated clock和source clock,以及source clock和master clock的关系,如果根据声明找到的generated clock 和master clock的关系和实际的关系不一致,否则会造成一些分析错误。 如:sta的时候找不到generated clock和source clock相位关系,会将generated clock的source latency 设置...
STA学习记录-时钟定义 (qq.com)1 generated clock的定义generated clock是有master clock衍生而来，master clock指的是由create_clock定义的clock当基于master clock生成一个新的clock时，可以将这个新的clock定义为generated clock举个栗子，如下图所示，UFF0的功能是将时钟CLKP进行二分频，那么便可以在UFF0的输出端UF...
master clock的source是时钟定义点,generated clock的source是master clock,因此在report中,clock path的起点是master clock的定义点 此外,master clock的latency也会直接作用于generated clock(也就是说在定义generated clock时不需要再指定latency) 先看一个例子 ...
Table 6–7. create_generated_clock Command Options 源延时是由于从主时钟(不一定是主管脚)开始的时钟网络延时所致。你可以使用set_clock_latency –source命令约束源延时。 Figure 6–17 展示了如何产生一个基于10ns时钟的反向生成时钟: Figure 6–17. Generating an Inverted Clock ...
master clock的source是时钟定义点,generated clock的source是master clock,因此在report中,clock path的起点是master clock的定义点 此外,master clock的latency也会直接作用于generated clock(也就是说在定义generated clock时不需要再指定latency) 先看一个例子 ...
since I'm sure the source clock and the target are coming to and out of the pll ( I don't get an error notification about the pin location ) my guess is that the issue is that " I need specify clock latency between clock and target." I see the PLL IP sdc is loaded , any ...
muxes, and clocks forwarded to other devices from an FPGA output port, such as source synchronous and memory interfaces. In the.sdcfile, enter generated clocks after the base clocks definitions. Generated clocks automatically account for all clock delays and clock latency to the generated ...
The delay between CLKA and CLKB is modeled as clock latency (both by TimeQuest and Classic). So, all you need to do is: create_clock -period 10 CLKA create_generated_clock -divide 2 -source CLKA CLKB TimeQuest will then do everything right. If you want to then ...